If you’re going to call it a vision …

Posted January 29, 2024 by waterbloguer
Categories: Uncategorized

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A development called Mirasol Springs is being proposed in Central Texas, along the Pedernales River on the Travis County–Hays County border. The development scheme is shown in the schematic below. It includes a “resort” hotel (the Inn), “branded residential” homes, “resort” cottages, “conservation” lot houses, a research facility, and a farm. This area is a somewhat “pristine” landscape, in particular including much of the – so far – “undisturbed” Roy Creek watershed, renowned by naturalists as a great example of a “native” Hill Country landscape. Thus it is considered an imperative to develop in this area with great sensitivity to this landscape, in particular in regard to water resources management, to blunt the draw on this area’s limited water supply resources and to minimize water quality degradation. The developer’s scheme proposing to accomplish that is set forth on the project’s website here, offering his team’s vision of how to best manage water resources – water supply, “waste” water management, and stormwater management. The “header” of this page reads, “Mirasol Springs will set a new standard for environmentally focused Hill Country development.” Raising the question, would it really?

As reported in “One Water” = the “Decentralized Concept”, there is a broadly supported, but so far largely unrealized on the ground, idea that engineering practice in this area needs to move toward “One Water” practices, and that a better understanding of the way we do this needs to be fleshed out. It was argued in that post that the “One Water” ideal would be most effectively and beneficially delivered by designing efficient water management into the very fabric of development, as if it were a central point, rather than to first arrange for water to “go away” and then to attempt to append on that efficient management at the “end of the pipe”, as if it were an afterthought. With the inevitable conclusion from this being that imparting “One Water” practice will rely in large part on employing distributed management schemes, such as the decentralized concept described in the piece linked above. Let’s take a look at how all that might play out in a setting like Mirasol Springs.

Water Supply

In the vision the developer sets forth on the project website, listed under “Water Use” are four components:  surface water, reclaimed water, rainwater harvesting, and groundwater.

Under “surface water”, the website states, “Surface water purchased from the LCRA [Lower Colorado River Authority] will be the base water supply for Mirasol Spring’s [sic] potable water and will meet 100% of our demand.” It is first brought to question, just how is this so very conventional idea – extracting a water supply from the watershed-scale rainwater harvesting system that supplies the vast majority of water supply in the Central Texas region – a “new standard”?

In this case, as can be seen in the graphic below, the proximate source of the potable water supply would be the Pedernales River, which runs along the border of the project site. The water withdrawn from the river would be pumped into a water supply reservoir to be built on the site. Water would be withdrawn from that reservoir and run through a water treatment plant. The treated water would be distributed in a conventional distribution system, routing water to all of the buildings on the development, requiring distribution lines to be extended to all the various developed areas on this site.

This conventional water supply system would entail a great deal of site disruption. This includes installing the intake structure in the river and a pump system and delivery pipe running up the bluff on the Mirasol Springs side of the river, and installing the reservoir, which would entail excavating the pond and distributing the excavated material on the project site. The distribution lines would cause disruption over and between the developed areas, in particular to get to all the “conservation” lots in the more “pristine” parts of the site, in the Roy Creek watershed.

Raising the obvious question, what could the developer do instead to create a water supply system for the project? Skipping to the “rainwater harvesting” component, the website states, “Rainwater collection from rooftops will be a requirement for larger structures constructed across the property, a practice that is already in use on the ranch. Deed restrictions for home sites will include water capture for irrigation purposes and guidelines for non-water intensive vegetative covers, water conservation-oriented landscapes and xeriscapes. Landscape irrigation on home sites will be restricted to rainwater collection only; no potable water will be allowed for landscape use.” While this laudably proposes to make rainwater collected on site from rooftops a primary supply for irrigation needs, it neglects considering the most “One Water thing” one could conceive here, maximizing the resource value of the water falling upon this site. So perhaps obviating all the expense and disruption of creating and operating the surface water supply system.

Consider the benefits of a water supply derived from distributed building-scale rainwater harvesting (RWH) vs. the surface water system. First and foremost is the efficient use of the area’s strained water resources. The very reason why the developer would pursue groundwater as a backup supply, reviewed below, is that they conceive the possibility that the Pedernales River would run dry, or dry enough to have their water supply curtailed. So why not consider the prospect of not depleting that surface water resource at all?

Second, as noted, with the facilities arrayed at the building scale, site disruption to install the storage pond and the water distribution system would be avoided. As would the inevitable leakage losses that plague such water distribution systems, so largely avoiding that often rather sizable source of water use inefficiency.

Third, the energy requirements to run the building-scale RWH systems would be considerably lower than would be required to run the surface water supply system. In the former, considerable energy would be required to lift the water from the river to the on-project water supply pond, and from the pond to the water treatment plant, and also to run the more energy-intensive surface water treatment unit, and then to pressurize and move water through the distribution system. In the building-scale systems, any lift from a cistern would be low and the water would only have to be run a very short distance. The treatment unit required to render the roof-harvested rainwater to potable quality would require far less energy than the conventional surface water plant. Not only would this be a fiscal plus for the MUD that will pay the energy bills, since it takes water to make energy – the so-called water-energy nexus – all this energy conservation would enhance the overall efficiency of the region-wide water system.

Fourth, under the surface water supply scheme, a considerable evaporative loss from the on-project water storage pond would be incurred, at its maximum just when drought would typically be at its worst. Evaporative losses from the covered building-scale cisterns would be minimal, a not-insignificant efficiency advantage for the building-scale RWH strategy.

Fifth and finally, pretty much the entire surface water system would have to be planned, designed, permitted and installed before the first building on the project could be provided a water supply. This is a hefty amount of up-front cost that must be incurred before any revenue-generating facilities may come on line, imposing a considerable “time value of money” detriment. The building-scale RWH facilities, on the other hand, don’t need to come on line until the building(s) each unit serves would be built, so the lag between incurring those costs and being able to derive revenue from each building could be much shorter. Also, it is expected that each of the building-scale systems – excepting for the Inn – would fall below the threshold to be classified as a Public Water Supply System, so the long and expensive process of permitting these systems through TCEQ could be avoided, a further “time value of money” benefit.

To determine the degree to which building-scale RWH could create a sufficient supply to meet the potable water demands in the buildings, a model would be used, into which the roofprint (water collection) area, the cistern (water storage) volume, and the expected water usage profile would be input. The model would be run over a number of years of historic monthly rainfalls to see how much, and how often (if at all), backup supply would have been needed in each year through the cycles of drought and plenty, and how much water supply would have been lost via cistern overflows during large storms and through extended rainy periods.

Based on the outcomes, “appropriate” building design, to increase roofprints – for example the “veranda strategy”, adding on covered patios and porches to add relatively inexpensive additional collection area – and “proper” cistern sizes, as well as the target conservation behavior, could be chosen to make the system as robust as desired. Past modeling of and experience with building-scale RWH in this region indicates that this strategy could provide a quite sufficient supply for much of the interior (potable) water uses at Mirasol Springs.

Through this means, the potential for building-scale RWH could have been evaluated, and the costs of using it could have been compared to the costs of the conventional surface water supply system. And the benefits of avoiding the site-wide disruption entailed in the conventional strategy could also have been evaluated. None of this appears to have been considered by the developer, rather it seems to have been simply presumed that the surface water supply, the watershed-scale RWH system, was “needed”, that building-scale RWH could be no more than an adjunct supply to defray irrigation usage. Opportunity to set an actual “new standard” foregone.

Now consider the “groundwater” component. The website says: “Groundwater will only be used if surface water is unavailable or curtailed. The goal of the project is to significantly limit the use of groundwater through conservation, including the use of reclaimed water and harvested rainwater, noted above, to meet non-potable water demands. When surface water is not available, Mirasol Springs will utilize groundwater to service the demand for domestic use. No groundwater will be used for landscape irrigation. Good stewardship of groundwater resources will be supported through additional planning and holistic water management measures. There will be no individual water wells. Water availability studies have demonstrated that adequate groundwater is available from the underlying aquifer when the project is required to use groundwater.” Quite a number of claims and caveats there to be considered.

While there is no indication what the parameters of the deal to purchase water from the LCRA may be, it is expected that any curtailment or unavailability would be predicated on the flow in the Pedernales River, which would rise and fall with cycles of drought and wetter times. If a drought were of such severity that river flow would drop so low that LCRA would curtail or ban further withdrawal of the surface water, it would be exactly such a time period that the region’s aquifers would also be under maximum stress.

There is no analysis, however, of “[w]hen surface water is not available”, and so when/if groundwater might be “needed” is entirely opaque. There is no indication, no standard for what would constitute “[g]ood stewardship of groundwater resources”, no idea offered for how those resources “will be supported through additional planning and holistic water management measures.” It all seems to be a “just trust us” proposition, hardly any sort of “new standard for environmentally focused Hill Country development.”

Thus, by plan, groundwater would be prevailed upon to carry the entire potable water supply just when that source too would be most stressed, and so when groundwater withdrawals would be most problematic. But again there is absolutely no analysis of when/if groundwater might be “needed”. So it may be called to question if indeed “adequate groundwater [would be] available from the underlying aquifer when the project is required to use groundwater.” There is no indication that a drought-stressed local aquifer could provide the full potable water demand over any given period, for this or any other developments in this area. Indeed, it is the questionable future condition of the local aquifer that urged the developer to look to a surface water supply to begin with.

Then too it can be called to question if the treatment requirements for a groundwater supply would be the same, using the same sort of treatment train, as for the surface water drawn from the river. Water quality of groundwater varies considerably across the Hill Country, and “over-drawing” aquifers can cause the quality of water from some wells to degrade. So this is another aspect of the overall scheme that appears to be a bit open-ended.

All this would be imparted by choosing to ignore the readily available “One Water” strategy, an actual “new standard” strategy, of maximizing supply from water falling onto this site.

“Waste” Water Management

While those water supply matters basically rest on analyses that the developer chose not to pursue, and almost certainly sells short the “One Water” supply strategy, in the “waste” water arena, there is a much more clear-cut choice. For the “reclaimed water” component, the website states:  “Mirasol Springs will reclaim wastewater from the Inn, the Farm, the University of Texas Hill Country Field Station, and all the home sites in a centralized collection facility that is aesthetically integrated into the landscape. There will be no septic systems. The facility will be equipped with the best technology available for nutrient removal and will reclaim 100% of the effluent for irrigation uses. This wastewater will be treated and used to offset irrigation needs for the property and other non-potable uses. No potable water will be used for landscape irrigation. Also known as beneficial reuse, this process completes the effort to maximize the lifecycle of water usage onsite. There will be no discharge into any creek or river. All wastewater will be collected and returned to a treatment plant.” This word salad begs for examination.

As stated, and as seen on the water systems graphic above, the developer is proposing that a conventional centralized system be installed, collecting all the “waste” water to be treated at one centralized facility. Including from the large “conservation” lots, entailing a rather long run of sewer line, in the Roy Creek valley, the most environmentally sensitive portion of this site, to collect a relatively small portion of the total amount of “waste” water that would be generated on the overall project. For those lots, to avoid the disruption and pollution — and the cost — those lines would impart, the developer should consider on-lot systems, to treat and reuse the water on each lot to serve irrigation demands there. Which, I expect, requires a dose of perspective.

It is noted that the website explicitly states, “There will be no septic systems.” Like that is a good thing. One can read between the lines here that “septic system” is deemed, at best, a secondary good, and likely is presumed to be a source of pollution, that the developer sees as being eliminated by centralizing the “waste” water from the various lots. Ignoring of course that components of the centralized system would themselves be pollution vulnerabilities. Conventional collection lines leak – longer runs of lines impart more leakage, and this becomes worse as the lines age – and manholes in those lines overflow. Lift stations inevitably needed in the terrain on this site will inevitably fail and overflow at intervals. And all this is in addition to the widespread disruption of the landscape that would be entailed in installing the centralized collection system.

This could all be obviated by choosing to pursue a decentralized concept “waste” water management strategy, treating and reusing the “waste” water as close to where it is generated as practical. Again, for the dispersed “conservation” lots, this would be a no-brainer strategy, presuming the use of the sort of “septic system” that is equal to the task at hand. A system providing high quality pretreatment – including removal of a large majority of the nitrogen from the “waste” water prior to dispersal – consistently and reliably while imparting rather minimal O&M liabilities. Then dispersing the reclaimed water in a subsurface drip irrigation field, arrayed as much as possible to serve grounds beautification, the landscaping that would be irrigated in any case, whether the reclaimed water was there or not, so practically maximizing beneficial reuse of the “waste” water resource in the on-lot environment.

The High Performance Biofiltration Concept treatment unit – set forth for distributed treatment duty in “This is how we do it”, and more fully described here – fits the bill here, being by its very nature stable, benign and robust. This is the very treatment technology used, for example, at the highly touted Wimberley “One Water” school, exactly because of that.

Unfortunately this treatment concept is not very broadly known, as the “septic system” market in Texas is so dominated by the “aerobic treatment unit” (ATU), which is a small, home-sized, bastardized version of the activated sludge treatment process, a process that is by its very nature inherently unstable, and even more unstable in these bastardized incarnations of the process. And, as reviewed in “Averting a Crisis”, the “septic system” regulatory process in Texas is legend for neglecting on-going O&M, so making it even more critical that “fail-safe” systems like the High Performance Biofiltration Concept be used, especially in a setting like Mirasol Springs.

Noting, however, that assuring “proper” O&M “shouldn’t” be an issue on Mirasol Springs, as the entire “waste” water system, no matter how deployed, would be professionally operated and maintained by the MUD the developer proposes to establish to run the water utilities on this project. All the more reason to use the inherently stable and robust, the more “fail-safe” High Performance Biofiltration Concept treatment unit instead of ATUs, to reduce the load on that O&M system.

Indeed, even the centralized treatment plant the developer proposes would be episodically loaded, with flows rising and falling through the diurnal cycle. So using an inherently unstable activated sludge system for that plant would be a vulnerability, urging the use of the “fail-safe” option there as well.

But again, the major vulnerabilities would be avoided by not centralizing all flows, rather by distributing the system to each building or set of buildings, as would be most cost efficient in each circumstance. Note in particular how this disperses risk. Any problem with the centralized treatment plant would impact on the entire flow, while a problem with any of the distributed treatment units would impact on only a minor fraction of the total flow. And again, there we would be using the low risk “fail-safe” treatment technology.

But the developer foregoes this opportunity, in fealty to the conventional understanding that it is best to centralize all flows to one treatment unit, despite all the pollution potential, and disruption, inherent in gathering flows to that central point. And despite the cost of running the collection lines out to each developed area, and – if the reclaimed water is to be reused for landscape irrigation as the “vision” asserts – the redistribution lines to send water from the central treatment plant to the areas to be irrigated. Again, all that would be avoided under the decentralized concept strategy.

Then there is the matter of the “time value of money”. The centralized system is an “all or none” proposition. The treatment plant would be initially built with the capacity to treat flows from all the buildings on the project, while portions of the development would come on line in phases, so that some of the treatment plant capacity would lie idle in the interim until the project was built out. It is also likely that the collection and redistribution lines would all have to be installed to get the water from all areas to the treatment plant and back to irrigation sites. Here too, investments would sit in the ground, not fully utilized, until the project built out.

A distributed system would obviate all that unrealized value. First by not having to install the collection and redistribution lines at all. And then, by using the improved type of “septic system” noted above, installed for each development area on a “just in time” basis, to serve only imminent uses. For development other than the “conservation” lots, likely a collective system serving more than one building at each treatment center, but still overall a distributed system, not requiring any investment in the larger-scale collection and redistribution lines. Further realizing the “time value of money” by building only those systems needed to serve imminent development, rather than having to plan, design, permit and install the entire centralized system before service could be provided to the first building.

As for treatment quality, the developer appears to presume a need for “the best technology available for nutrient removal”, even though all the reclaimed water would be dispersed in subsurface drip irrigation fields, providing all the treatment and “buffering” that the soil-plant complex offers. The High Performance Biofiltration Concept treatment unit can consistently and reliably produce an effluent with low – typically about 10 mg/L – BOD and TSS, the two basic measures of how well treated the water is. 20-30 mg/L is deemed “secondary” treatment, which is the minimum required to disperse the reclaimed water in subsurface drip irrigation fields. This is mainly to assure that drip irrigation emitters would not clog, as the level of “dirtiness” of the water as measured by BOD and TSS, as long as it is in the “secondary” range, is otherwise irrelevant in a soil dispersal system.

The High Performance Biofiltration Concept unit can also routinely remove a large majority of the nitrogen from the “waste” water, typically producing an effluent concentration of about 15 mg/L. Less than 20 mg/L is deemed to be a “safe” level that would, along with plant uptake and in-soil denitrification we have in this climate, result in a vanishingly small amount of wastewater-derived nitrogen flowing into environmental waters when dispersed in a TCEQ-compliant subsurface drip irrigation field.

Phosphorus – the pollutant of greatest concern in discharges to streams – would be irrelevant here, since at the concentrations found in domestic wastewaters, phosphorus would be fully “sorbed” in any soil mantle that would provide a decent growing medium.

Bottom line, the High Performance Biofiltration Concept treatment system would deliver an effluent that would be highly protective of the environment, even in this sensitive area, assuming of course that the subsurface drip irrigation systems were well designed, well implemented and well operated. Which of course would be the same condition that the conventional system the developer proposes would have to meet.

The conclusion is that the decentralized concept strategy described here, utilizing distributed “fail-safe” treatment units and dispersing the reclaimed water into subsurface drip irrigation fields, would produce a “waste” water system for this project that would be more fiscally reasonable, more societally responsible, and more environmentally benign than would be offered by the conventional centralized system – with reuse appended on – that the developer proposes.

Stormwater Management

The website is light on how stormwater would be managed on this project. It states under the heading “Watershed Protection and Storm-water Runoff”, “The ultimate goal is to maintain the hydrology of the environment in its current state. This will be accomplished through short-term construction site management strategies that include silt fencing, soil berms and wattles to prevent erosion and silting of nearby streams.” Which seems to sequester the efforts to mitigating water quality degradation due to construction activities. Necessary of course as the development is being built, but the major task is to indeed “maintain the hydrology of the environment in its current state.”

In that quest, the website states, “There will only be a few homesites in the Roy Creek watershed, all with a 1,000-foot land buffer between the home [and] Roy Creek [sic]. The engineers recommend allowing for the native vegetation and soil to act as a natural ‘filter,’ as it has done for thousands of years, rather than trying to capture it and then release it from a pond or other structural water quality controls that would unnecessarily disrupt the natural character of the land.” The actual solution here is restricted to the “conservation” lots only, leaving it open what is to be done elsewhere, but implying the only option is the conventional view of stormwater management, that the site “should” be efficiently drained into an “end-of-pipe” facility – “a pond”. It seems to deny the “One Water” strategy of collecting and infiltrating the runoff on a more distributed basis, the Low-Impact Development (LID) strategy utilizing permeable pavement, Green Stormwater Infrastructure (GSI), etc.

The obvious measure of maintaining “the hydrology of this environment in its current state” is to render the rainfall-runoff response of the developed site as close as practical to that of the native site. This dictates that, up to the rainfall depth where runoff would begin on the native site, after all the “initial abstraction” were “filled”, all runoff should be intercepted and caused to infiltrate. While some of that infiltration might be imparted by flow over the “natural filter” in downslope areas, more generally some of that infiltration would have to be “forced”, with permeable pavement or by running it through GSI, such as distributed rain gardens. It seems the developer has not considered this basic “One Water” concept, choosing to rely on a more conventional end-of-pipe management scheme. Perhaps entailing the installation of grey infrastructure to convey flows from developed sites to ponds and such, as seems to be implied in the “Mirasol Water Systems” schematic above. It is called to question how well this could maintain the rainfall-runoff response very similar that of the native site.

The website further asserts, “Considerations will also include restrictions on impervious cover to prevent run-off and divert water into the aquifer.” Disregarding the non-sequitur, it should be clear that the LID/GSI strategy, infiltrating runoff from impervious surfaces on a highly distributed basis, is the manner in which one could reasonably “prevent run-off and divert water into the aquifer”, particularly on the more intensive portions of the development, like the Inn and resort cottages, perhaps the “branded residential” homesites too. We’d just have to deal with pavement, since rainwater harvesting would basically take rooftops “out of play”. The water that would have infiltrated over the area covered by rooftops would be captured, stored and later infiltrated, either through irrigation directly or once used in the buildings and becoming “waste” water, then irrigated. That concept was explained in this post.

Now as noted the 1,000-foot “land buffer” would indeed be quite effective in mitigating pollution and the increases in runoff imparted by development on the “conservation” lots, but of course there would have to be constructions to cause any concentrated flows to disperse into overland flow, so the scheme would not be quite so “automatic” as the website appears to present it. GSI, such as full infiltration rain gardens, should be installed there as well, to intercept flows off of impervious covers, to directly infiltrate some of the flow and to spread flows over that “natural filter”. This would be particularly so for any rainwater cistern overflows, which would be “concentrated” flows out of a pipe.

The website is totally silent on this LID/GSI approach — the “One Water” approach — implying that the only option the developer can conceive to letting stormwater runoff flow away downslope would be to first route it to “a pond or other structural water quality controls that would unnecessarily disrupt the natural character of the land.” Noting of course that it is the disruption of the “natural character” of the land caused by development that any such constructions would be installed to mitigate. Again this seems to reflect that conventional bias for gathering runoff into end-of-pipe “ponds”, rather than running it through highly distributed constructions like full infiltration rain gardens, with only “large” storm runoff overflowing on down the slope. Somewhat better mimicking the hydrology of the native site.

Summary

So it is that the water “vision” of the developer can readily be called to question. To sum it up, if the developer of Mirasol Springs is going to style its water management scheme as a “vision”, then perhaps it should impart some. It should follow the best “One Water” practices available in this setting, the water supply, “waste” water management, and storm water management practices reviewed above. Presenting the conventional scheme the developer proposes as a “new standard” can be quite fairly seen as simply greenwashing that very conventional scheme. If this project is to deliver on its promise of preserving and protecting this “pristine” landscape, a more holistic, more “One Water” strategy will be required.

Or so is my view of this matter. What’s your view?

Moving off top dead center …

Posted December 6, 2023 by waterbloguer
Categories: Uncategorized

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Awhile back I attended a confab put on by the Save Barton Creek Association (SBCA) at which was discussed a couple of developments south of Austin, in the vicinity of the City of Hays and the City of Buda, labeled “Hays Commons” and “Persimmon”. The presenters, representing SBCA along with the Save Our Springs (SOS) Alliance and the Greater Edwards Aquifer Alliance (GEAA), asserted that the scale and nature of these developments were “incompatible” with the area and represented a threat to water quality, as they were on or adjacent to the environmentally sensitive Edwards Aquifer Recharge Zone. All of this was presented in rather general terms, as the presenters did not have any actual development plans to show, just generalities about the scale and nature of the proposed projects. And the only actual “prescription” the presenters seemed to have was “just don’t build there”.

But of course, this being a capitalist society, the folks who own that land have investments, and are no doubt responsible to investors who expect a return on their investment. So in an attempt to further the conversation and maybe get into how we might blunt or obviate the problems that the presenters asserted would be imparted by the developments they feared, I asked the obvious question, what would you have these folks do with this land instead? This seemed to have stumped them, but one of the presenters eventually said, “more of the same as what’s there, 1-acre lots on septic.” Apparently unaware of the impacts of that development concept on land fragmentation, and how unfriendly to water quality the types of “septic” systems the county will approve would be. See, for example, Averting a Crisis.

Leading me to understand, we need to have a conversation about what sort of development folks think “should” be the manner in which much of the Texas Hill Country develops. Because in the current market, develop much of it will. So I set my mind to looking at the land upon which the Hays Commons project was being planned.

Some years ago I had met with the owner of that property, Bill Walters, to talk about the manner in which he might install water and “waste” water service to develop that property. This was years before any thought of extending City of Austin water and wastewater utility lines might have been entertained that far out from the limits of their system at that time, and even back then the limited supply capacity from the aquifer was understood, so our conversation centered on what folks might term today “One Water” practices, that term having come into vogue in the interim. We talked about using building-scale rainwater harvesting (RWH) for water supply, and about distributed (decentralized concept) wastewater systems that would focus on producing a reclaimed water supply to serve non-potable demands, to reduce the draw on the “original” water supply source. Also a heavy dose of low-impact development (LID) stormwater management techniques, to greatly blunt the impacts of development on runoff water volume and quality.

I could see how these concepts might allow Walters to install water and wastewater services on Hays Commons in a manner that would save him time and money while we all saved water. You see, the working plan of Walters’ development partner Milestone is to get the City of Austin to extend water and sewer lines to the project. That would, of course, require a very significant investment up front, to install the waterlines, pump stations, and storage tanks, and to install the wastewater mains and lift stations. Note that in addition to those line extensions, the developer would still also have to install water distribution lines and sewer lines within the development. Which would all take quite a bit of time, during all of which the actual development – the thing that would produce revenue for the developer – would have to cool its heels. And because of those high up front costs and time delays, the developer would be highly motivated to go with a more intense development scheme. That too would entail costs and further time delays to the developer to deal with opposition to denser development from the likes of SBCA, SOS and GEAA, as we’ve already seen.

Enter a better plan, a “total One Water” scheme, to eliminate most of the up front costs and the delays that spending that money would entail, and to also save a whole lot of water. AND it would also greatly blunt water quality degradation. Here is that scheme, as I set it before Walters:

First, thank you for taking some of your time to talk with me about the project next to the City of Hays, about the prospects for considering a water infrastructure plan that would have rather reduced up-front costs and regulatory approvals timeline, and would be more sustainable. We need to be pursuing sustainable water strategies, of course, as that’s really a matter of long-term sustainability, including having the water supplies to continue to develop in this region. A current series of articles in the New York Times is highlighting how America is draining away a “legacy” groundwater supply, overdrawing aquifers all over the country. Which of course is true around here. Indeed, one wonders, are we really acting in a manner such that we’re planning for only One More Generation, and after that, we really don’t have a plan? So maybe this development should be “saved” from becoming just one more exponent of that “one more generation” attitude?

For water supply, you noted that you’ve drilled 3 wells on this property, each of which was found to yield enough flow to support at least some of the desired development. Given the drought-induced issues with declining aquifers around here, one must wonder just how sustainable those yields may be. So maybe consider greatly “extending” that supply with a “conjunctive management” scheme, entailing:

  • Create a PWSS [public water supply system] using one or more of the wells as its water supply source. Determine which buildings would have a level of service that would rise to the level needing the water supply to be a PWSS, and install a limited distribution system to those buildings only. That, along with the permitting of the PWSS, and of course one or more ground storage tanks, would be all of the water supply facilities that would need to be “papered”, financed and installed prior to being able to start selling those lots to builders, and to start building on them.
  • The rest of the development – be they commercial or residential properties – would employ building-scale RWH as the water supply strategy. This would entail no up-front costs, as the whole water supply system would be built as the building is built. And with building-scale RWH at a level of service that does not rise to being classified as a PWSS, there would be very little regulatory burden.
  • Of course, the building-scale RWH systems should be designed and installed so as to be as sustainable “as practical”. This would dictate that building roofprints may need to be larger than would “normally” be the case for the sorts of buildings being considered. And that of course would have impacts on building styles, so the developer, and builders, would have to be willing to consider all that.
  • As for how to accommodate the “large” roofprints, please consider what I call the “veranda strategy” for adding relatively less expensive roofprint, by adding “verandas” around the building. By this means, expanded roofprints that would render RWH systems sustainable through worse drought periods can be provided relatively cost efficiently. So we’d want to look at the sorts of spaces the developer wants to be able to market, and consider if buildings housing those spaces could be practically built, and marketed, to provide the needed roofprint.
  • Of course, there would be a cost for the cisterns required for each building-scale RWH system, but perhaps this cost could be blunted – if not “relieved” altogether? – by lower lot prices availed by there being very little up-front costs to create an overall water supply system.
  • The PWSS drawing from the well would also be the source of backup water supply for the building-scale RWH systems, if drought became too severe and the building-scale RWH systems’ cisterns became depleted. This would put control of backup supply availability within the development, so that all owners of RWH-served properties would be assured of having a backup supply whenever needed. The backup supply would be delivered from a ground storage tank via tanker truck, so that a backup water distribution system would not have to be installed.
  • Because a very large fraction of the total water supply needed in the development would be provided by the building-scale RWH systems, so “relieving” the aquifer of that routine demand, the aquifer level could be somewhat “preserved”, so that the water would indeed be there if needed as supplemental supply during prolonged drought periods.
  • Note that buildings to be served by building-scale RWH may be started, and marketed, without having to wait for the several month (minimum) permitting process for the PWSS, and for getting those facilities designed, bid and installed, so likely imparting a “time value of money” benefit.

I trust you can see the “charm” of such a scheme, in particular from the developer’s standpoint due to the low up-front cost of water supply infrastructure, and the minimization of regulatory lead time in order to begin selling lots and building on them. Again, this could be so without regard to the overall intensity of development proposed on this property … within limits, of course; there’d have to be room for the larger roofprints and such, but the overall development intensity would have to become rather “extreme” for that to functionally come into play, seems to me.

For the “waste” water system, the idea would be to creatively plat lots for “condo” development, with the total amount of development on any given lot imparting a design flow rate <5,000 gallons/day (gpd), so that the “waste” water systems could all be “septic” systems, or On-Site Sewage Facilities (OSSFs) in rules-speak, permitted at Hays County – nominally a 30-day permitting time – rather than TCEQ-permitted “municipal” systems, entailing a year or more to permit and a whole lot more paperwork, thus more cost for technical and legal services. This scheme would entail:

  • Determining the building types desired to be developed and how they may be arrayed on the property. Then gathering them into groups that would create a total design flow rate <5,000 gpd, and platting lots surrounding each such group of buildings. All of the buildings would be under “condo” ownership, with the ground being owned in common. These are the conditions required in order to use OSSFs for the “waste” water system, since TCEQ kicked “cluster systems” out of Chapter 285, the on-site wastewater rules, in 2003, and has never seen fit to formulate a “middle way”, short of the far more onerous “municipal” permitting process, in the 20 years since.
  • Presently, Hays County rules include a requirement that each lot covers an area large enough so that the total design flow rate would not exceed the equivalent of 300 gpd/acre. So for a 5,000 gpd system, the minimum lot size would have to be 5000/300 = 16.67 acres. 5,000 gpd would cover 27 2-bedroom houses or 20 3-bedroom houses, so even with this restriction, a net density of over one house per acre would be attained.
  • In working on another project that was proposing to similarly use OSSFs for the “waste” water service, it was floated to Hays County that the 300 gpd/acre requirement might be applied over the whole property, rather than imposed lot by lot. This would allow using non-lotted property – e.g., the floodplain on the property in question – as a part of the required area, and so allow denser development on the lots. Hays County had responded favorably to that proposal. (Unfortunately that project “died” due to the Dripping Springs development moratorium, so that concept was never tested and confirmed.)
  • Presuming that the 300 gpd/acre rule did not limit the total number of units that could be installed on this property “too severely”, or if that rule could be “excused”, then it’s pretty clear that this “waste” water service plan would entail no up-front costs to the overall project developer, other than what Hays County would require during the platting process to show OSSFs could provide the required level of service. This can very readily be done by posing a standard OSSF design using the High Performance Biofiltration Concept (recirculating packed-bed filter) treatment unit, which would disperse the high quality effluent this unit would consistently and reliably produce in subsurface drip irrigation fields. This is the most environmentally benign sort of system that could be practically employed in such a distributed management system.
  • Each lot owner – which may be the overall project developer, or the developer(s) who would build on each lot – would then plan, design and install the OSSF to serve the buildings on that lot. This process would entail fairly minimal lead time, after the lots had been platted and made available for building upon.
  • The drip fields would ideally be arrayed to irrigate the highest value landscaping on each lot, likely to be grounds beautification around each building, or high value common areas, like a park or “common”. Note it is not at all uncommon to import soil to create “improved” soils for landscaping around houses and other buildings in the Hill Country, so we’d be placing the drip fields in the best soils on the property. In any case, the soil depth would have to be shown to meet the rules over the whole field area, something that’s not very well “guaranteed” in land application systems under the municipal permitting process.
  • By these means, most (all?) of the grounds irrigation would be taken off the potable supply, so rather drastically conserving the overall level of water use on this property.
  • There would of course be a management system created. Formally, each OSSF would have to be covered by a maintenance contract with a TCEQ-qualified/licensed maintenance company. In practice it would be most rational to have one “master contract” that would maintain all the OSSFs on the whole development, making this essentially the “wastewater utility” covering this development. By assuring that this management system was organized and run to properly oversee the OSSFs, long-term good performance could be practically assured.
  • It may be that some buildings – like the commercial buildings that it is understood would be part of the desired development plan – could implement a flush-water recycling scheme, further saving water supply. In such buildings, only a small “residual” wastewater flow would be created by water used in lavatories, slop sinks, break room sinks, etc., and that flow could be readily dispersed over the landscaping around such buildings. Again optimally focused on maintaining the highest value landscaping, the grounds beautification. That sort of scheme was discussed in Appropriate Technology.
  • Finally, by not collecting all the “waste” water in a conventional centralized scheme, we’d avoid the environmental liabilities inherent in that configuration, due to line leaks, manhole overflows, lift station bypasses, and from the disruption inherent in installing conventional sewer lines. So this distributed scheme is inherently more environmentally benign simply by how it is arrayed.

I trust you can also appreciate the “charm” of this scheme for the project developer, as it minimizes up-front costs for the “waste” water infrastructure and time delays for dealing with regulatory processes.

Part and parcel of the overall development scheme would be a very robust LID/green infrastructure stormwater management scheme. This would be designed to retain at least as much water on the land as infiltrates, rather than runs off, on the “native” site, so as not to “desertify” the land by draining “away” the increased runoff imparted by covering the land with impervious surfaces and otherwise modifying the land surface. By this means, water quality impacts of stormwater runoff would also be practically minimized. That scheme could be rather readily designed into each lot as it is developed, so here also entailing minimal lead time to design and install. That strategy would minimize any need for end-of-pipe ponds and such, which may also pose an up-front cost and time delay that could be avoided.

By going with this sort of sustainable water infrastructure scheme, society would be saving a lot of water – that is my main interest, indeed getting society to create more sustainable water systems, to start planning beyond “one more generation” – while saving the developer time and money.

Unfortunately, when presented with this “total One Water” scheme, Walters and Milestone proved to be strangely uninterested in saving time and money, and as far as I know are still pursuing utility extensions from the City of Austin. But you can see the potential here for a development scheme that would indeed save time and money for the developer, save water for society, and would significantly blunt water quality degradation. It also avoids sprawl-inducing utility extensions, the cost of which would mitigate for more, and more intense, development, exactly the outcome we’d like to avoid on this land. This sort of win-win-win might provide a template for how the environmentally sensitive Hill Country is to be developed, again noting that in the current market in this region, a whole lot of it will be developed.

So I would urge SBCA, SOS, GEAA and their allies to consider all this, to move off top dead center, and urge developers to be a bit more creative and innovative than going with “1-acre lots on septic.”

Or so is my view on this matter. What is your view?

“One Water” = the “Decentralized Concept”

Posted October 16, 2023 by waterbloguer
Categories: Uncategorized

I am part of a group that is putting together a course, perhaps to be offered by Texas A&M, to teach the “One Water” concept, culminating with a “certificate” that is expected to have some meaning for practice in this arena. The major activity in the first gathering of that group was to set forth ideas on what the course content should cover. As a “conversation starter” I offered the group a rundown on what the “components” of a “One Water” scheme might include. A major theme of that document was that “One Water” schemes would be basically “distributed” concepts. Let’s explore that whole idea.

A working definition of “One Water” is offered by the Meadows Center for Water and the Environment at Texas State University as:

“One Water is an intentionally integrated approach to water that promotes the management of all water – drinking water, wastewater, stormwater, greywater – as a single resource.” [emphasis added]

This definition can be illustrated in practice by these examples:

  • Wastewater and water supply can be integrated by designing and developing the “waste” water system to focus effort and resources on producing a reclaimed water supply, preferably close to the point of reuse, which would be utilized to defray demands on the “original” water supply to the project.
  • Stormwater management and water supply can be integrated by capturing the additional runoff caused by development, in cisterns and/or landforms, rather than allowing it to “efficiently” drain “away”, with the captured water used as explicit water supply – e.g., building-scale rainwater harvesting, using water captured from roof runoff into cisterns to defray, or displace, demands on the “original” water supply – or to enhance the hydrologic integrity of the site by maintaining the rainfall-runoff characteristics of the “native” site on the developed site, holding water on the land instead of “desertifying” the land by draining “away” water that would have otherwise infiltrated to maintain deep soil moisture, to recharge aquifers, etc.

These examples highlight a fundamental imperative of “One Water” practice – to maximize the sustainability of water supplies, these integrated management strategies must focus on addressing all water as a resource to be husbanded, not as a “nuisance” to be gotten rid of, to be wasted as expeditiously as possible, which has been the focus of conventional stormwater and wastewater management practice. Of course, the water does not actually “go away” – the hydrologic cycle is a closed system on a global scale – but those practices are wasteful in that they expend resources to route the water out of, rather than to maximize its beneficial use within, the immediate environs. Each gallon that is so externalized (wasted) is another gallon that must be imported into the project, and (in this region particularly), all existing water supplies are becoming increasingly strained.

A basic principle, highlighted for example by Paul Brown of CDM – a voice from the very heart of the mainstream – in his preface to Cities of the Future, is that water is most sustainably managed by maximizing the beneficial use of these resources within the project, as much as practical, “tightening up” the loops of the hydrologic cycle, rather than externalizing those resources and then importing water from “traditional” supplies to make up for these externalized – wasted – resources. By following this “One Water” practice, the developer, the eventual users of the project, and the community-at-large will realize fiscal, societal, and environmental benefits.

A simple schematic comparing a non-integrated – or “silo’d” – system with an integrated management system is shown in the figures below, illustrating how husbanding of the water resource may be enhanced by this “tightening” of the water loops. As this illustrates, the same overall function might be obtained while imparting about one-half the draw on the “original” water supply to a project.

As this illustrates, the “One Water” methods would integrate into the land plan, rather than being appended on, divorced from the land plan, as is typical under the “silo’d” conventional management strategies. In short, water resources sustainability would be designed into the very fabric of each project. And thus, we see that “One Water” would typically be most effectively accomplished by decentralizing the water resources management infrastructure.

Before proceeding, it is important to acknowledge that context is important, and in each circumstance, the full range of available options should always be evaluated, including both “centralized” and “decentralized” schemes. So while it is presented here that distributed infrastructure seems typically more likely to produce the better “One Water” schemes, there will of course be instances in which a more conventional looking “centralized” infrastructure would prove to be the “better” option. For example, in an area with the conventional centralized “waste” water system architecture already in place, the “best” option for assuring that “waste” water realizes its resource value may be the installation of a “purple pipe” system to redistribute water from the centralized treatment plant to points of reuse.

Moving on … While as noted the intention should always be to integrate the various water management functions, in practice each of them – water supply, “waste” water management, and storm water management – are typically addressed individually, with the “integrations” generally falling out of the means and methods that are utilized. Referring to the examples listed above, water supply and “waste” water management could be integrated by utilizing the “waste” water resource to defray demands on the “original” water supply source for the project being served by that “waste” water system. Note that the water supply system itself would not be “perturbed” by this scheme, it’s just that part of the supply would now be shunted off to the “waste” water being reused to create that adjunct supply.

Generally, as also noted above, that integration, the defraying of water supply demand, would be maximized by designing that whole process into the very fabric of the development. Which brings us to the “decentralized concept” of “waste” water management.

Noting that the “One Water” concept generally entails “tightening” the water loops, integrating water management into the very fabric of development, it becomes rather obvious that “waste” water systems would be “distributed”, rather than “regionalized”, as is the mantra of much of conventional practice. The “decentralized concept of ‘waste’ water management” – set forth quite consistently by the author over the last 37 years – embodies this whole idea. This is an alternative organizing paradigm for a “waste” water system of any overall scale. Here is the basic idea, as set forth in a 1988 paper by the author:

“Stated simply, the decentralized concept holds that wastewater should be treated—and the effluent reused, if possible—as close to its source of generation as practical. In particular, it is suggested that the first stage of treatment—for which a septic tank is preferred, as outlined later—be placed at or very near to the wastewater source, regardless of how centralized the rest of the system is. The conventional “on-site” system might be viewed as the ultimate embodiment of this concept, and on-site systems might indeed be the appropriate technology for parts of the service area. In areas where soil and/or site conditions dictate that conventional on-site systems would not be environmentally sound, the septic tank effluent might be routed through further treatment processes before dispersal or reuse.

“However, the concept is very “elastic”.  In practice, it may be beneficial to aggregate several waste generators into one septic tank or to route septic tank effluent from several generators into a collective treatment and dispersal system.  The most appropriate level of aggregation at any stage of treatment would be determined by a number of considerations, such as topography, development density, type of land use, points of potential reuse, or locations where discharge is allowable.

“Judicious choice of technology at each stage of the collection and treatment system can help advance fiscal, societal and environmental goals.”

Note in particular three items in that description:

  1. The term “waste” is in quotes to highlight that “wastewater” is a complete misnomer for designating what, within a “One Water” concept, must be addressed as a water resource to the maximum extent practical in each circumstance.
  2. The over-arching aim of “wastewater” management is not “disposal” – as basically defines conventional practice – rather must be focused on producing a reclaimed water, to be used to defray demands on the “original” water supply to the project being served by the “waste” water system, to the maximum practical extent in the circumstances at hand.
  3. With the overall system distributed, practical operation of multiple distributed treatment units demands that “judicious choice” of technologies to be used to assemble the system.

This all leads to identifying the basic “tools” of the decentralized concept, as has been set forth by the author and others in any number of works in this field, those tools being:

  • Effluent sewerage is highly favored for any collection of “waste” water beyond the building site level. This is the concept of intercepting flows at, or very near to, the site of their generation in septic tanks – termed “interceptor tanks” within the effluent sewerage concept because they intercept the “big chunks”, leaving only liquid effluent with very low levels of settleable solids to be transported any further, so allowing the use of effluent sewers, instead of conventional “big pipe” sewers. This reduces the cost of the “remant” collection system that remains in the distributed system and minimizes the environmental impacts of the collection system, practically eliminating leaks, bypasses and overflows, not to mention minimizing the degree of disruption entailed in installing the smaller, shallower effluent sewer collection lines.
  • Treatment beyond the septic tank must be done with “fail-safe” technologies. The term “fail-safe” is in quotes because any sort of treatment unit must be properly operated and maintained so as to continuously and reliably produce the expected effluent quality, but certain technologies, by dint of their very nature, are more robust and “forgiving”, and so can stay “on track” with rather minimal O&M effort and attention. This is essential to creating a management system that would not become overtaxed by needing to police the multiple treatment centers that following the decentralized concept would create. What types of treatment units that fall into the “fail-safe” category, and how to design those units will likely be a matter of opinion in this field. It is the author’s long-held view that inherently stable technologies like the recirculating packed-bed filter and constructed wetlands be highly preferred in lieu of the activated sludge process that is practically the “knee-jerk” choice in conventional practice. This is because the activated sludge technology is inherently unstable, an effect that becomes more problematic in “smaller” treatment plants, really anything but the treatment plant being “based loaded”, as is extant only in large “regional” treatment plants.
  • Again, the fate of the effluent, the reclaimed water, is to serve water uses that would need to be met whether or not the effluent were available for that usage, and to properly apply the reclaimed water to serve those demands, and so defray demands on the “original” water supply source. It is to be expected that irrigation is likely the most “available” and readily served use in many cases. In particular in climates such as exist in this region, for which subsurface drip irrigation – itself a “fail-safe” technology of sorts – should be preferred, to maximize irrigation efficiency – also of course a basic “One Water” principle” – and to sequester the reclaimed water underground to minimize potential for human contact in the highly distributed reuse sites. Other uses may include toilet flushwater supply, cooling tower blowdown makeup, and perhaps even laundry water supply.

An example of how these tools could be employed to create a decentralized concept system strategy was reviewed in “This is how we do it”, showing the benefits, in particular to practically maximize the resource value of the “waste” water, of the decentralized concept scheme vs. a conventional development-scale system or a conventional centralized system.

Thus we see that in terms of “waste” water management, “One Water” basically equals the “decentralized concept” of “waste” water management. This strategy focuses investments on properly treating and effectively reusing the water resource, rather than on just moving the stuff around – which is all the far-flung collection system within the conventional centralized system architecture does – by eliminating most of that collection system. Employing creative system concepts and more “fail-safe” technologies, this scheme also makes the overall system cost effective to operate, and blunts environmental impacts inherent in “waste” water management.

Under a “One Water” strategy, water supply and storm water management would also be generally more distributed systems than they are under conventional practice.

The “traditional” view of storm water management centers on “efficient” drainage “away” from the development of increased runoff imparted by development, so as not to impart nuisance flooding of project grounds, and to assure that as this water flows “away”, it does not create downstream problems, either due to streambank erosion or overbank flooding. This “efficient drainage” viewpoint often results in whatever constructions used to attain those aims being “end-of-pipe”, essentially appended onto the project, rather than distributed facilities designed into the very fabric of the development. An essential “One Water” strategy is to “retain, not drain” the runoff, at least up to the point that this water would have infiltrated rather than flowed “away” from the “native” site. The aim is to maintain as much as practical the “hydrologic integrity” of the site – that is, to maintain the rainfall-runoff response as similar to that of the “native” site as practical – and by treating multiple sites in a watershed in this manner, to maintain rather than degrade the hydrologic integrity of the watershed.

The means by which this would be accomplished would be implementing the “low-impact development” (LID) concept, imparting rainwater harvesting – either “formally” in cisterns or by capturing runoff in specialized landforms generally termed “green stormwater infrastructure” – on a highly distributed basis. Again, designed into rather than appended onto the development. When I first learned of LID, it immediately hit me that this is basically a “decentralized concept of storm water management”. So here too, “One Water” = the “Decentralized Concept”.

An example of this sort of distributed LID concept was illustrated in “… and Stormwater Too”, showing how rainwater harvesting from rooftops, permeable pavement, and rain gardens (bioretention beds) would create a highly efficient scheme to both hold more water on the land and to utilize the rooftop runoff to further defray landscape irrigation demands.

Regarding water supply, not only would building-scale rainwater harvesting (RWH) typically be a component of the storm water management scheme – so potentially creating a supply that could be used to defray water demands rather than just being drained “away” after being detained in the cistern – but some, even all, of the water supply strategy could be based on building-scale RWH. This all plays into what I have termed the Zero Net Water concept.

True to its name, Zero Net Water is a water management strategy that would result in zero demand on our conventional water supplies – rivers, reservoirs and aquifers. Under the Zero Net Water development concept, water supply is centered on building-scale rainwater harvesting, “waste” water management centers on project-scale reclamation and reuse, and stormwater management employs distributed green infrastructure to maintain the hydrologic integrity of the site. So basically it’s really another name for “One Water”. Together these result in minimal disruption of flows through a watershed even as water is harvested at the site scale and used – and reused – to support development there. In the general case, this concept might be approached – you might call it “minimum net water” – to defray but not eliminate demands on the conventional water supply sources.

Our conventional supply systems are watershed-scale rainwater harvesting systems, utilizing reservoirs, aquifers and streams as the “cisterns” to hold the water supplies awaiting various uses. Noting that an essential water use is maintenance of environmental integrity – e.g., maintaining aquifer levels so as not to reduce spring flows, keeping enough flow in streams to service various environmental functions, including delivery of water into bays and estuaries to maintain those ecologies. So we need to be saving as much water as we reasonably can, and minimizing disruption of flow through the watershed. The “minimum net water” approach would serve that end.

While it will not be belabored here, distributing the water supply system to the building scale creates an inherently more efficient system, as it eliminates transmission losses and evaporation losses from reservoirs, and it requires less energy, as the water needs to be moved only short distances, with small elevation heads. It would also be more economically efficient, as the water supply would be “grown” – thus paid for – in fairly direct proportion to water demand, one building at a time.

In closing, a more recent focus of “One Water” practice is the capture of air conditioner (AC) condensate, applying the water so captured to providing water supply, to defray demands on the “original” water supply source to the site. Clearly, condensate capture would also be a very highly distributed strategy, executed at the building or campus scale.

So it is that not only does “One Water” = the “Decentralized Concept” in the “waste” water management arena, “One Water” would optimally be a rather highly distributed strategy for water supply and storm water management as well. Moving from the conventional centralized “waste” water system architecture to the decentralized concept strategy has been a challenge for the mainstream of this field. Over the almost 4 decades I’ve been advocating for that paradigm shift, very little movement has been seen on that front. It is to be expected that moving off “end-of-pipe” management to a highly distributed LID strategy, and integrating building-scale RWH into the water supply strategy on a broad scale will be similarly challenging to the field, as these moves also require a paradigm shift.

Despite the “One Water” concept having been “a thing” in this field for many years now, despite years of “happy talk” around moving society toward a “One Water future” and such, we have seen precious little of all this hitting the ground. To the extent that, when a local environmental activist queried the U.S. Water Alliance – a major “cheerleader” for “One Water” – on examples where “total One Water” schemes, entailing all the water management functions, could be found, the response was … [crickets chirping]. One wonders, how much is that lack of movement in practice due to the paradigm shift to more decentralized schemes not having taken hold in the water resources management field? Indeed, we have a lot more work to do before it will become broadly recognized that “One Water” = the “Decentralized Concept”. But until that happens, it’s highly likely the movement toward “One Water” will continue to be very slow.

Or so is my view on this matter. What’s your view?

Be a beaver

Posted May 13, 2023 by waterbloguer
Categories: Uncategorized

I recently read the book Water Always Wins by Erica Gies. A major theme is that to best manage water resources as they flow through our environment, in particular to promote and enhance sustainable water, we need to be imparting a “Slow Water” regime. We need to use management methods that blunt the rushing off of runoff and instead install means and methods that slow the flow, causing it to spread so that more of the water soaks in instead of running off. By these means, Gies argues, we can retain, and restore, the hydrologic integrity of sites, and by so treating a multiplicity of sites, of the watershed, so it would deliver more water supply.

A chapter in the book is about beaver, the undisputed champion in the animal kingdom at modifying and improving the hydrology of watersheds. The instinctive dam-building activities of beaver indeed create a Slow Water regime. They dam the flow, causing water to spread across the floodplain, filling up the “sponge” that landform creates, so storing much more water in the watershed than would occur otherwise. This slowing and retention of the water decreases downstream flooding, as more rainfall is detained/retained rather than zooming downstream. A good bit of this retained water would over time augment downstream baseflow, so improving the riparian ecology. The dams also retain sediment and so improve downstream water quality. All of this also stores carbon, and so helps to blunt climate change.

It struck me while reading that chapter that being like a beaver and creating a Slow Water regime is essentially what we did in the Villa Court project. The 3505 Villa Court project lies between Garden Villa and South 5th Street, in the Bouldin Creek watershed in South Austin. It’s a 13-unit townhome project that was installed on 1.43 acres of formerly “vacant” land. The final layout of the project imparted 67% impervious cover of the land.

In 2010, I was approached by PSW, the developer of many townhome projects in Austin, to help them obtain the water quality permit they would need to execute this development. They related that a senior level person in the City of Austin Watershed Protection Department had told them, “You need a retention-irrigation system.” Won’t bore you with the details of that method, except to say it would have entailed encumbering the back yards of all the townhomes along the downslope edge of the property with tanks to store the runoff, and taken up just about every square inch of greenspace in the development plan to “irrigate” the water gathered into those tanks. I looked at that for, oh, about 2 or 3 nanoseconds, then said, “This is insane.”

I told them, we could provide the water quality treatment for this project with rain gardens, and we could do that without needing any variances. This surprised them, and the folks at Watershed Protection too, as no one had run this idea at them before that. But I showed them that the rules did indeed support the rain garden scheme. Besides meeting the formal water quality management requirements, the rain gardens would capture and insoak the “excess” runoff created by development and keep about as much water on the land as had been soaked up by the land in its “natural” state. This despite a rather high percentage of the land having impervious cover. So we proceeded to be like a beaver.

“Rain garden”, as a formal water quality device, is a term often used for a full infiltration bioretention bed. This device is a vegetated bed of a specialized soil mix that intercepts runoff from its drainage area. Under Austin rules, the volume of water to be captured is termed the “water quality volume”. This is the volume of runoff from the drainage area generated by the “water quality depth” of runoff from the area. The water quality depth required to be captured under Austin rules increases with the percentage of impervious cover over the drainage area tributary to each rain garden. The idea is that the more impervious cover, the more the balance would be shifted from infiltration to runoff of rainfall, so a larger volume of water would need to be captured in order blunt that shift.

The captured water volume would be stored in the bed until it is infiltrated into the soil under and surrounding the rain garden. This process both intercepts pollution entrained in the runoff – “treating” it as it flows down through the biofiltration bed root zone – and retains the water quality volume on site, rather than allowing it to run directly off, so helping to control and mitigate downstream flooding and channel erosion.

The 3505 Villa Court water quality management plan entailed several rain gardens, distributed around the site. Five of them intercepted runoff from rooftops, pavement and green spaces. Another seven captured runoff from a rooftop that could not be routed to one of the other five rain gardens, so that these areas of impervious cover would be “treated”. The project layout is shown in the figure below.

This shows how indeed we intercepted, spread and infiltrated runoff flows. As noted, this restores to some degree the rainfall-runoff response of the “natural” site, as it blunts the increase in runoff immediately leaving the site that installing impervious cover on the site would otherwise impart. This indeed mimics to an extent the impacts that beaver have on a stream, only this is applied in the uplands rather than in a streambed, intercepting and insoaking the increased runoff on its way to a stream. But the ultimate impact is largely the same, damming up the flows, holding – storing – water on the land. And reaping the benefits of that.

Some of this water would infiltrate and ultimately migrate to a stream, to impart baseflow, just as water seeping out of the floodplain “sponge” that beaver create would impart baseflow downstream. As noted, the rain gardens also intercept and store sediment entrained in runoff, just as beaver ponds do, and also intercept and “treat” pollutants that developing land causes to be entrained in runoff. Then too, there would be carbon sequestration in the rain garden beds. So in imparting the water quality management scheme at Villa Court, we were being like a beaver, mimicking the ecological wisdom they evolved to deliver to the landscape.

Now of course the retention-irrigation scheme, entailing interception of runoff and subsequently spraying it over landscape to largely infiltrate the water that would have otherwise run off, would have also helped to maintain the hydrologic integrity of the site. But that would have been acting like a human, using a failure-prone mechanical system, requiring assured power supply, to redistribute the water over the site. Noting that little actual irrigation benefit would be obtained by spraying the captured runoff over the green spaces, because the storage tanks have to be evacuated only a couple days after the rain fell, which had just “irrigated” those spaces. Any sediment removal would have to be accomplished by “actively” cleaning the storage tanks, into which the “raw” runoff would flow. Rather than incorporating the sediment into the plant-soil system on the site just as a matter of course, this would create a “waste” stream that would have to be “disposed of”. Then too, the shallow-rooted turf that would be “irrigated” would not sequester anywhere near the level of carbon that the deep, more biologically complex rain garden root zone would.

All this illustrates we would be well served to be like a beaver in the way we design sites for water quality management, in the manner we did at Villa Court. Damming up water flows to create a Slow Water regime at the site level, holding up and spreading out the flows, infiltrating on the site “excess” runoff imparted by development, rather than it rushing away, so retaining/restoring the hydrologic integrity of the site. And by a multiplicity of such sites in a watershed, we can retain/restore the hydrologic integrity of the watershed. It could fairly be stated that if every site in the Bouldin Creek watershed had been treated like Villa Court was, we would still have baseflow in Bouldin Creek. And that would enhance the ecology of the whole watershed.

Almost like re-introducing beaver to the watershed would. So when considering how to manage storm water as a site is being developed, be a beaver.

Comment

Posted March 28, 2022 by waterbloguer
Categories: Uncategorized

March 28, 2022

Office of the Chief Clerk, MC 105

Texas Commission on Environmental Quality

P.O. Box 13087

Austin, TX 78711-3087

COMMENTS TO TCEQ REGARDING “PRISTINE STREAMS PETITION”

A petition, styled as the “Pristine Streams Petition”, permit no. 2022-014-PET-NR, has been filed with the Texas Commission on Environmental Quality (TCEQ) requesting that TCEQ adopt a rule that would bar any discharges from TCEQ-permitted “waste” water treatment plants into 23 stream segments that monitoring has found to have very low “native” concentrations of phosphorus. The aim of this proposed rule is to keep these stream segments “pristine”, in regard to their phosphorus concentrations, and thus free of “excess” algae growth that it has been documented “waste” water effluent discharges into such streams will induce.

I agree that such a rule should be promulgated, in an attempt to accomplish its stated aim. This rule is truly the minimal effort that the State of Texas should consider in an effort to blunt degradation of water quality in the waters of the state. It is in fact rather astounding that it would take a petition to get TCEQ to consider such a rule, as protecting “pristine streams” from the sort of degradation due to “waste” water discharges that have been witnessed is really in the “no-brainer” category. But as is reviewed below, establishing such a rule really needs to be just the beginning point of a larger effort to improve the state of “waste” water management in the state of Texas, including – if not especially – in regard to the fate of this water resource that we mistakenly identify as “wastewater”.

You see, a very basic problem that plagues this societal function is that TCEQ insists upon viewing this function through the lens of “disposal of a nuisance”, when really what society needs – in this region in particular, with the looming water supply issues we face – is for us to address this function with a strong emphasis on “utilization of a resource”. As TCEQ appears to “understand” this function, it is required that a full-blown “disposal” system be in place before an applicant can even start to consider the resource value of the water and how best to reuse this water so as to defray demands on the “original” water supply.

The practical outcome of TCEQ’s insistence on the “disposal of a nuisance” focus is that it is difficult to design reuse into the very fabric of development, so as to practically maximize the reuse benefit of this water resource. Which is how we should be addressing this societal function, just as a matter of course.

Under the “disposal of a nuisance” construct, the permitting process is typically a two-part endeavor; first a permit for the “disposal” system, and then another permit to route this water resource to reuse. The “clunkiness” of this process is an open-ended “invitation” to applicants to just throw this water resource away, to just do the “disposal” system and not incur the extra work, and cost, of addressing the reuse part. That is why it has been witnessed that the majority of “land application” systems are in effect “land dumping” systems, with the effluent routed to “disposal fields” – where any irrigation benefit is just coincidental – as the manner in which to make this water “go away”. Indeed, in every reference to the Dripping Springs application to expand its dispersal fields, for example, the proposed fields are called “disposal” fields. Indeed, while Dripping Springs asserts that they intend to reuse their effluent rather than “dispose” of it, it appears that all their efforts to date indeed focus on “disposal”, with no actual reuse system infrastructure being apparent. This is a dynamic that has to be blunted, with the process reoriented to focus on the beneficial reuse of this water resource, if local society is to most effectively address its looming water supply crisis.

Then too it must be recognized that centralization of “waste” water issuing from miles around to one point source treatment plant is the whole predicate for even considering stream discharge as the fate of this water resource. Indeed it is a motivator to just discharge into a stream to “get rid of it”. Once the “waste” water has been gathered to that one point source, stream discharge will always be the “cost efficient” way to “manage” that flow (depending perhaps on whether TCEQ would assign effluent limits that would not degrade the receiving stream’s water quality, which it does not seem inclined to do), especially given the high cost that would already be incurred to gather that flow to the centralized point source. A large majority of the total cost of a conventional centralized “waste” water system is the cost of the collection system, investments that really do nothing but move the stuff around, not really contributing to resolution of the root problem of managing that water resource. So once a community has dedicated a considerable investment to making that water “go away”, they would be less than excited to incur a similar investment to redistribute this water resource from the centralized point source to points were it could be beneficially reused, often being back where the water came from in the first place!

So it is that we should be considering how we can decentralize the “waste” water system, to shorten the water loops so as to minimize the investment dedicated to just moving the stuff around, and better enable designing reuse of this water resource into the very fabric of development. But this runs afoul of TCEQ’s “regionalization” policy, stated in TAC Chapter 26.081. That this holds sway over the institutional infrastructure that addresses this societal function is attested to in Dripping Springs’ “moratorium” ordinance, which states that the city “understands” the conventional centralized system architecture to be the only form of “waste” water system infrastructure that is “blessed” by TCEQ. As if this is religion, not science and technology, so that no considerations of the form and function of that infrastructure that do not conform to the “Book of TCEQ”, Chapter 26, verse 081, is allowed to be countenanced. A moment’s reflection should be plenty to conclude that there is more than one way to skin this cat. But at present it appears that most of our institutional infrastructure will not countenance any such reflection. Again, as if this is religion.

The need for re-examining the infrastructure model is perhaps most critical in exactly the areas such as those where those 23 “pristine” streams lie. A major reason they remain “pristine” is because there has been little development in areas tributary to these streams. So these are places where we have a “blank slate”, where we are not beholden to sunk costs in the conventional centralized system architecture, so could readily entertain another infrastructure model. That was, for example, the situation in which Dripping Springs found itself, yet again they chose fealty to the “Book of TCEQ” over a rational consideration of the full range of options available to them.

One such option is a “decentralized concept” strategy. Cut to its most basic, the decentralized concept holds that “waste” water is most effectively and efficiently managed by treating, and reusing to the maximum practical extent, the “waste” water as close as practical to where it is generated. As noted, this approach would work with, rather than against, the whole idea of integrating reuse into the very fabric of development, as if management of this water as a resource from its very point of generation was a central point. Rather than considering that whole matter as something you might append on to redistribute the water gathered at the end of the pipe, as if the whole matter of this water being a resource was just an afterthought.

This “decentralized concept” idea has been out there for decades, having been the subject of many works considering the concept, much of it funded and conducted under the auspices of EPA. Indeed, a “finding” was issued by Congress in the 1990s that this general approach is a legitimate manner of addressing “waste” water management needs. It is generally understood among those who have chosen to examine this matter that the decentralized concept strategy has the potential to produce “waste” water systems that are more fiscally reasonable, more societally responsible, and more environmentally benign than those systems which implement the conventional centralized system architecture. But in practice any meaningful consideration of the road not taken has been blunted, so that good examples of such practice remain rather few and far between. In no small part due to such circumstances as “regionalization” being an “article of faith” in TCEQ.

However, in the context of “developing” areas, this matter has been presented to TCEQ, and to society’s various institutional actors – city administrations and utility operators, the engineering community, the development community, and the environmental community. An example of this was presented on the Waterblogue in 2014, entitled “This is how we do it” (https://waterblogue.com/2014/09/24/this-is-how-we-do-it/, considered to be part and parcel of this comment), showing in the context of one development in the Dripping Springs hinterlands how a reuse-focused decentralized concept strategy could work in that environment, in a manner that would not only integrate reuse into the very fabric of the development, thus maximizing ability to defray demands on the “original” water supply, but would also be more globally cost efficient than centralizing that development into a Dripping Springs “regional” system. The fiscal, societal and environmental advantages of this strategy were further reviewed on the Waterblogue in 2016, in the piece entitled “Let’s Compare” (https://waterblogue.com/2016/09/26/lets-compare/, considered to be part and parcel of this comment). This application of the concept was explicitly reviewed with TCEQ, and it was the conclusion of the folks with whom it was reviewed that this strategy could be permitted under current rules. So it could readily deliver those fiscal, societal and environmental advantages in many developments in the hinterlands, such as those that may be installed on or near the “pristine” streams, NOW.

So it is that there is ample reason to reconsider the “dogma” of “regionalization” and to consider the road not taken. In particular in areas where there is little sunk cost in the ground that must be respected going forward, such as the areas where, in the main, those 23 “pristine” streams are located. Reinventing the “waste” water system infrastructure model in those sorts of areas can deliver systems that are more fiscally reasonable, more societally responsible and more environmentally benign than would be attained by pressing down on the cookie cutter and spewing out the conventional centralized system architecture, without regard to the nature of the circumstances. TCEQ must examine this matter and consider how it can best serve the citizens of Texas in regard to how the “waste” water resource is to be managed, especially around those “pristine” streams.

So again, please do protect those 23 “pristine” streams from “waste” water discharges. This is simply a “no-brainer” thing to do. But also open up the whole process of planning for how growth and development will be managed in such areas, to take a long hard look down the road not taken. As that all the difference could make. [apologies to Robert Frost]

Respectfully submitted,

David Venhuizen, P.E.

Austin, Texas

Cognitive Dissonance

Posted November 1, 2019 by waterbloguer
Categories: Uncategorized

Perhaps a child has told us what the deal is.

I have long been mystified about why folks around here behave as they do about the water issues we are facing in Central Texas. For many years, an array of interest groups have been asserting “I’m for the Hill Country, are you?”, that they are dedicated to opposing wastewater discharges into Hill Country creeks, and to moving us toward sustainable water management there. Lately, the flavor-of-the-month with those folks has been the “One Water” idea, that all the water that flows through our communities is a resource to be husbanded, rather than much of it being addressed as if it were a nuisance, to be made to go to that magical place we call “away”. I trust that anyone who has read much of this blog will recognize that is exactly what has been urged upon society here.

But it does not seem that these folks behave in concert with their declarations of how “important” all this is to “saving the Hill Country”, as they have so far not engaged in any real advocacy for the move toward sustainable water. I have often exhorted them to do so, and that always seems to be interpreted, as one of those folks once put it, that I’m “being mean to good people trying to do good things.” So why, I’ve often wondered, do they so often not really act in accord with what they espouse, why do they not actually advocate for the actions that can put what we need to be doing about all that on the ground?

Just as an aside, before we proceed, there is of course the possibility that they just don’t believe that my “prescriptions” for our water issues are “correct”. If so, then I’d challenge them to read this blog and say exactly what they disagree with. And I’d also note that, on occasion when these folks do get at all explicit about what needs to be done, they generally espouse essentially what has been set forth in this blog, that we do indeed need to transform our water resources infrastructure model, to put it generically – again, the “One Water” model. So onward …

A few weeks ago, I happened to watch the PBS Newshour interview of Greta Thunberg, the Swedish teenage climate activist who has been heard from in several quarters lately, perhaps most famously her address to the United Nations. In the course of that interview she said when asked why the climate crisis does not seem to be taken seriously even though people seem to be agreeing there is a problem, “They say one thing and then do another thing. … Cognitive dissonance.”

She went on, “I think it is because humans are social animals. We follow the stream, and since no one else is behaving like this is a crisis, we see that and then think, I should probably behave as they do.” When asked why she doesn’t “follow the stream” herself, she offered, “For me, I’m on the autism spectrum, and I don’t usually follow social coding, so therefore I go my own way, and I think that is a very strong reason why people just continue, because they don’t see anyone else reacting to this.”

So maybe it’s as simple as that. Cognitive dissonance. Folks say they don’t want “bad things” happening in the Hill Country, but when it is set before them what are the ways of proceeding that would blunt all that, they simply cannot seem to bring themselves to actually, explicitly advocate for those ways of proceeding. Perhaps that is because they look around, see that the entire mainstream is behaving as if “business as usual” is the way we “should” approach it – the very mental model that this blog has been dedicated to combating – and they pick up on the social queues and determine that bucking the apparent consensus, that appearing to not be “in the tribe”, would not be a “proper” way to act.

So perhaps I also am somewhere on the autism spectrum, because I also don’t “follow social coding”, as Thunberg put it, and go my own way in the water resources arena. Perhaps I cannot see that “social coding” says one does not so directly challenge the mainstream as I do, and one certainly does not question the behavior of those who assert they are in concert with what I am advocating but then do not act in concert with those assertions. And so each attempt to “enlist” them, to get them to act in concert with their own assertions is simply taken as one more instance of me “being mean to good people trying to do good things.”

Okay, so maybe that is an “explanation” for why nothing that’s been set forth about all this, such as in this blog, has been rallied around by the very folks who have asserted they want to attain the ends that I’ve been asserting those actions would attain. But if that really is the case, isn’t that rather disturbing? Isn’t the logical conclusion here that these people have chosen to be “sheep”, that it is more important to them to “fit in” than to act in accord to their asserted beliefs and aims? How can we accept that all of the “thought leaders” in all of the organizations that have set forth their desires for the how the Hill Country will fare as development occurs there could prioritize not looking like they are not “in the tribe” above attaining the ends they assert they want to attain?

But what is the choice? It is very clear that these folks do not actually advocate for the actions that will lead to attaining the ends they espouse. One very straightforward example is the “waste” water system in Wimberley. Over a decade ago I started advocating that they consider a 21st century infrastructure plan as they considered how to implement an “organized” wastewater system there. Much of that is reviewed here. And five years ago, I laid out rather explicitly for the city management the sort of system concept that might essentially be called a “One Water” adaptation of the conventionally organized system they were pursuing. I did everything but draw them a picture. Yet despite broad dissatisfaction among all the “water activist” types around there with how the city was then planning to proceed, hardly anyone said a word about this option, and certainly no one put forth an iota of effort to press the city to actually examine it. So it was ignored, and the city proceeded with a conventional 19th century infrastructure model, which has since come apart for various reasons. Fast forward – right now these same folks are reported to be scrambling to try to get what has been generally described as exactly the sort of approach I laid out 5 years ago before the City Council commits to hooking the city center up to a conventional centralized system in the adjacent town of Woodcreek. So if these folks were not failing to stand up for a sustainable water approach back then so as to avoid appearing to not be part of the tribe, what was their “reasoning”?

But we should hope there is a way forward. In response to question, “Why do you have hope that we will, as a global society, react?”, Thunberg said, “I think that people are good, people are not evil, at least not everyone, most people, so I think people are just simply unaware of the situation, and people are not feeling the urgency. I think once we would start treating this crisis as an emergency, people will be able to grasp the situation more.” Which would indicate that, here also in regard to our water resources issues, it may just be that these folks are simply not “aware enough” of the situation, that they still need to have their consciousness raised before they will galvanize and act. Again, that runs counter to their own narrative – they already loudly decry the threats to the Hill Country and their “dedication” to blunting them.

So, while it’s an unsettling conclusion, it does appear that there has been no groundswell of advocacy for the sustainable water strategies, such as have been advocated in this blog, due to this cognitive dissonance. I continue to hope that folks will take that under consideration, and evaluate their actual dedication to “saving the Hill Country” in the water resources sphere. Perhaps a real, effective program of advocacy for transforming the water infrastructure model will be embraced when these folks “start treating this crisis as an emergency.” Thank you, Greta.

 

APPROPRIATE TECHNOLOGY

Posted September 17, 2019 by waterbloguer
Categories: Uncategorized

Last June the City of Austin ran a water conservation conference, and among the presentations was a review of Austin Water’s plans to incentivize, or perhaps require, building-scale “waste” water treatment and reuse for all projects housing over 250,000 sq. ft. of floorspace. As that presentation was winding down, the current assistant director of Austin’s Watershed Protection Department came by and whispered, “You were ahead of your time.”

He and I had met in 1986, exactly because I had just written “The Decentralized Concept of ‘Waste’ Water Management”, the first of many versions of that and similar works setting forth the idea that, by organizing the system to treat – and reuse to the maximum extent practical – the “waste” water as close to its source as practical, we would produce an infrastructure model that would be more fiscally reasonable, more societally responsible and more environmentally benign. He was in a business at that time, selling building-scale wastewater treatment units, for whom that basic idea was rather central. As he moved on through stints at various agencies and consulting firms, somewhere along the way he seemed to have “lost” that vision. I recall a conversation on his back patio, about 10 years ago when he was with a mainstreamer national consulting engineering firm, when we discussed how cities would manage water, he opined that my “vision” of decentralizing down to the building or campus scale would never be embraced, rather cities would always stay with the conventional centralized, pipe-it-“away” scheme. So it was, I can only guess, he felt a mea culpa moment, as some version of the very vision I’ve espoused these last three decades was being displayed in front of us as the direction Austin Water is moving.

However … As the presentations, and subsequent discussions with Austin Water folks, made clear, the means by which they expect to implement building-scale reuse is by using the tools of conventional centralized systems. Most particularly the inherently unstable activated sludge treatment technology, which is practically the “knee-jerk” choice of the mainstreamers, pretty much because it is deemed the “reasonable” choice in conventional centralized systems. Which brings us to the idea of appropriate technology for the scale of the system.

A central tenet of the decentralized concept, set forth in that original 1986 paper, is that the nature of the technologies used to assemble the system should recognize that, with distributed systems, there would be many more treatment units to police, so to minimize the total O&M liability, these systems would need to employ “fail-safe” technology. As I set forth in those early writings on this subject, there is a difference between “fail-safe” and “reliability”. A system can be reliable if it has the capability, when properly operated and maintained, to consistently and reliably produce the advertized effluent quality. But “fail-safe” means that the inherent nature of the technology is such that it can maintain reliability in the face of non-optimal operating conditions, because the technology is robust, inherently resistant to “upsets”.

Activated sludge technology is inherently unstable because it depends for its treatment action on very few trophic levels of microorganisms living in concentrations far higher than found anywhere in nature (a trophic level is a rung on the food chain—organisms on a higher trophic level eat organisms on a lower trophic level), thus it is a very truncated ecology that is not inherently sustainable.  The process can only be kept “on track” by maintaining proper operating conditions with constant inputs of energy to aerate the wastewater and monitoring the process to maintain a proper food/microorganism (F/M) ratio. Typically maintaining the F/M ratio requires frequent withdrawals of sludge from the system, on a time scale measured in hours. So failure to pay close enough attention leads to an “upset” in very short order. Therefore, while the process can be reliable, as long as proper operating conditions are maintained, it is not “fail-safe” because it is so sensitive to adverse conditions. Such a process is not really what you want to depend upon in a context like a building-scale reuse system.

So for highly distributed systems, like these building-scale reuse systems, we need to be using “fail-safe” technologies. Before proceeding, note that I always put “fail-safe” in quotes. Nothing is ever completely fail-safe. No matter how robust a technology may be, it will always require proper operation and maintenance if it is to be expected to continue to perform reliably. Again, there are certain technologies that, by dint of their very nature, are rather more immune to adverse conditions than the inherently unstable activated sludge technology, and for which the timing of O&M procedures is not so critical.

While various versions of constructed wetland technology may have merit – the Hassolo on Eighth project in Portland, Oregon, is an example of a project-scale reuse system that employs this technology – for my money the recirculating “sand” filter should be the “workhorse” technology of the decentralized concept. I put sand in quotes, because while the original version of this basic technology did use sand media in the filter beds, modern versions of it use “packed beds” of gravel media, geotextile fabric media, Styrofoam bead media, foam rubber media, etc. To cover all the different media that might be used, a more generic name for this technology is recirculating packed-bed filter.

Reasons why the recirculating packed-bed filter technology is inherently “fail-safe” include:

  • This technology is an attached growth, rather than suspended growth, concept, with the treatment effect accomplished by organisms attached to the filter media, harvesting food from the pollution in the water as it flows on by. Attached growth is far less prone to “wash out” than suspended growth, so the treatment effect is inherently much more robust and stable.
  • The loading rates on recirculating packed-bed filters are quite low, on the basis of microorganism “density” relative to the food source – this imparts a high mean cell residence time in the system – which renders the process more resistant to “upsets” and so enhances the stability of the treatment process. Again it is quite robust.
  • Power is not required to maintain the treatment process. Rather power is only needed to move the “waste” water to the top of the filter bed, and the actual treatment process is passive, imparted as the water flows down through the media by gravity. So, in sharp contrast to the activated sludge process, loss of power does not result in loss of the treatment process. If a power outage were to occur, the biota would sit there, waiting for the flow to resume, with no impact on treatment quality.
  • Flow equalization is inherent in the treatment concept, with the filter beds being loaded at the same hydraulic application rate on the same schedule every day, without regard to how much or how little flow enters the system on any given day. This hydraulic steady state operation renders the process highly consistent and reliable. This is particularly important in buildings with the occupancy patterns of commercial and institutional buildings, with high activity during the day, on weekdays, and little through the night and on weekends.
  • The biology of the system is quite diverse, typically including many trophic levels of microorganisms, and some macroorganisms as well. This characteristic also renders the process inherently resistant to upsets, allowing it to readily accommodate situations where system loading is highly non-uniform, as it will be in this circumstance.
  • The only moving parts are the pumps that dose the filter beds and a passive valve that operates on water level. Again, loss of pump power over the “short term” would have no impact on the treatment process, and a malfunction of the valve can be accommodated for some time before the treatment process may be impacted, allowing the operator to fix the valve essentially at his/her leisure.
  • The pumps are installed inside sealed tanks, setting under water, so would impart no noise pollution.
  • The only odor production might be imparted as the water is distributed over the filter beds. These units are sufficiently well covered so that odors would not be obtrusive.
  • Sludge management is very unobtrusive. The major mode of sludge management is pumping the septic tanks that are the “front end” of the treatment unit. This is typically only required at multi-year intervals and is not time-critical – months could pass between observation of sludge level in the septic tank indicating pumping is needed and the pumping actually being executed without any significant impact on the treatment process.
  • The system, once set up, basically “operates itself” day-to-day. There is nothing to adjust, and only infrequent routine maintenance is required.
  • Operations and maintenance activities for this system are rather simple and straightforward. They can readily be conducted by personnel with minimal training. As long as the control system components are not themselves proprietary, it does not rely upon any one vendor for this service.
  • The major “failure” mode of this technology is clogging of the filter bed. This occurs very slowly, allowing time for the operator to respond essentially at his/her leisure. With insightful design, filter bed clogging can be remediated in very short order.

My approach to building-scale, or campus scale, treatment and reuse was informed by learning from Takashi Asano back about 1990 that the California Title 22 reuse rules basically specified a system composed of a “waste” water treatment unit followed by a water treatment unit, to produce very high quality effluent for “unrestricted” reuse, such as for toilet flush water. Of course, being mainstreamers, the folks who wrote those rules set the water treatment requirements in terms of conventional water treatment plants, entailing coagulation-sedimentation-filtration. But it immediately occurred to me that for small-scale implementation of this concept, perhaps the slow sand filter should be the water treatment plant part of the scheme, for similar reasons that the recirculating packed-bed filter is favored for the “waste” water treatment part of the system.

While sand filtration had been used for water treatment for centuries, the slow sand filter concept as we know it today was first used in Scotland in 1804, and was first implemented for public water supply in London in 1829. It became widely adopted – it was first used in the U.S. in Poughkeepsie, New York, in 1872 – and despite the introduction of more “modern” water treatment processes, it continues to be used for municipal water treatment, including by many large cities, particularly in Europe. Like the recirculating packed-bed filter technology, the slow sand filter is “low tech”, being rather simple to operate and maintain, rather robust and largely “passive”. Indeed, it is these characteristics that make it the go-to water treatment technology in “third world” settings, where operating capabilities may be quite limited. That, of course, also makes it a great choice for distributed systems.

So it is that I suggest that the “standard” treatment unit for building-scale or campus scale reuse projects be composed of a recirculating packed-bed filter for basic “waste” water treatment, followed by a slow sand filter, to produce a near-potable quality water. UV disinfection of the treated water completes the system. A schematic of this sort of system is shown below. Indeed, one of the presentations, by Amelia Luna of Sherwood Design Engineers, at the Austin water conservation confab last June noted this as a good candidate for this duty. Notably, system concepts she highlighted do use the recirculating packed-bed filter unit as the “waste” water treatment portion of the system.RBPF-SSF TREATMENT UNIT

Besides its inherent “fail-safe” nature, this “low-tech” recirculating packed-bed filter/slow sand filter treatment concept would entail significantly less energy use to run it, imparting a much lower carbon footprint. The blowers in an activated sludge plant run 24/7/365, and in the versions using a membrane rather than a conventional clarifier to produce the final effluent – the version certain to be used in a building-scale system – quite a bit of power is also required to force the water through the membrane. By contrast, the pumps in the “low-tech” unit run only intermittently, needing to impart only a modest lift of the water to the tops of the filter beds, so drawing far less power.

It is also quite likely that the installed cost of the recirculating packed-bed filter/slow sand filter unit would be somewhat lower than for the activated sludge unit of the same capacity. Confirming this awaits an opportunity to design a unit for an actual application, but the cost factors seem to favor the “low-tech” unit.

Because there is not a whole lot of economy of scale for installed costs of the “low-tech” facilities, the cost per gallon for a 1,000 gallon/day (gpd) unit would not be greatly increased over the cost per gallon for a 5,000 gpd unit, so this scheme could be just as readily used for smaller projects as for buildings having 250,000 sq. ft. of floorspace. For example, a 250,000 sq. ft. office building might house 1,250 persons, and a 50,000 sq. ft. office building might house 200 persons. The Texas on-site wastewater rules set forth a design flow rate criteria for office buildings of 5 gallons per person per day, imparting a design flow rate of 1,000 gpd for the 50,000 sq.ft. building, and 6,250 gpd for the 250,000 sq. ft. building. If the costs do scale fairly uniformly over such a range of design flow rate, the building-scale reuse scheme might be just about as cost efficient for the smaller building as it is for the larger building. This would make it feasible to cover a much larger segment of the commercial-institutional building market with project-scale reuse than just the “big box” buildings.

Indeed, we have the opportunity here to create Zero Net Water commercial and institutional buildings and campuses. With the water use “intensity” in these buildings – that is, the amount of water demanded relative to the size of the building – such buildings would have adequate roofprint so that building-scale rainwater harvesting (RWH) could provide the “original” water supply, for lavatories and building grounds irrigation, while the building-scale reuse system supplies the flush water. Again, this appears feasible for buildings much smaller than 250,000 sq. ft.

This strategy would be especially beneficial for managing the “nodal densification” proposed by the “Imagine Austin” plan. This suggests that various properties within already urbanized areas would be redeveloped at higher activity levels, or “density”. Implicit in this is that more water supply would have to provided for that “node” and more “waste” water would be generated there. If managed conventionally, this would surely require upsizing water and wastewater lines in that area, which would probably entail “upgrading” the existing lines. For example, the densification of Austin’s downtown area required the installation of a 60-foot deep tunnel to pipe the increased flow of “waste” water “away”. That is all expensive and disruptive. Meeting these increased demands instead with a Zero Net Water strategy – RWH for water supply and decentralized concept “waste” water reuse systems – would obviate all that. Instead of importing more water and draining “away” more “waste” water, the water supply would be gathered and looped around within the “node”, to serve a building or campus of buildings. Then too, growth would be adequately served without increasing demands on our conventional water supplies, which are becoming increasingly strained in this region. RWH would also reduce stormwater management issues in the denser development.

So to summarize, Austin Water should seriously consider appropriate technology as it determines if and how to incentivize, or require, building-scale reuse in commercial and institutional buildings. They should consider implications for cost and reliability. By pursuing this function with systems composed of appropriate technologies, it is more likely that the concept would be more trouble-free, and thus more widely accepted, even embraced, as it becomes clear that we can save water and money by engaging in the fundamental transformation of the form and function of our water resources infrastructure that the decentralized concept strategy accomplishes, creating a system that is more fiscally reasonable, more societally responsible, and more environmentally benign.

A space traveler lands in Austin …

Posted November 26, 2018 by waterbloguer
Categories: Uncategorized

In 1999, I gave a presentation at an EPA-sponsored conference on urban infrastructure, featuring “visionaries” focusing on where we were expected to be headed to deal with water resources. Looking back on that presentation, because I’ve been accepted to make a very similar one at the Western Water Summit next year, thought it might be interesting to observe how little of that “visioning” has come to pass, how little has changed in the almost 2 decades since then. We seem to remain stuck on the prevailing, essentially 19th century infrastructure model, which is not serving us too well here in the 21st century. And we are seeing the consequences of that in many places and situations, such as around here in the Texas Hill Country, where the infrastructure model is the whole key to avoiding overt degradation of Hill Country waters with “waste” water discharges. Here is the “script” for that presentation, annotated to give context on what was being shown to the audience.

Our water resources infrastructure:

How we got here, why we’ve stayed so long, and where we’re going

Imagine with me that you are a space traveler who has just landed on earth, right here in Austin.  Since you’ve just gotten here, you know nothing of the traditions that have shaped our water resources infrastructure.  You can only see the results.

You look around and see that these earth people are producing most of the water they use to sustain their lives and societal functions about here (presentation showed location of water treatment plant that has since been decommissioned). This water is treated to potable standards, at considerable expense, and that water is transported in a hugely expensive system of pipes to a far-flung service area, such as way up here (presentation showed service area many miles away from that water treatment plant).

Well okay, you say, they’ve got to have water.  But THEN you see through your beady red alien eyes that they use this expensive water—ONCE!!—mostly for uses that do not require fully potable quality water!  Then it is dumped into another hugely expensive system of pipes to be transported way over here (presentation showed location of Austin’s wastewater treatment plant) to another treatment plant that is also very expensive to build and operate, to be partially treated and then dumped back into the river!  And you further observe that the transport system consists of conduits that sometimes leak and overflow, and of pump stations that sometimes fail, and that the treatment plants these earthlings use employ a very “touchy” technology that is very prone to upsets, so poor quality treatment is not an uncommon occurrence.

You also see that, in this particular case, that system of pipes and pump stations is arrayed over a sensitive recharge zone for an aquifer that serves as the source of drinking water to a considerable population.  You hear that in fact one of those pump stations had catastrophically failed not long ago and polluted that aquifer.

You notice that earth people also have the same attitude toward rainwater that falls on areas that could be used to capture it for direct use.  These could be the best, most pure water supplies available.  But considerable investments have been made to flush rainwater “away” in a “hydraulically efficient” manner.

You look at all this and say, “Huh, what WERE these people thinking?!  Why do they treat all this water to irrigate lawns and flush toilets and supply cooling towers and industrial processes – uses that don’t require such highly treated water – at the same time they’re flushing away all this rainwater and once-used water, at considerable fiscal cost and environmental hazard?”

Then you look at the biosolids that result from the treatment process, and you hear that there is a problem with recycling this resource back into the environment because of contaminants that come from certain industrial processes.  You can’t believe they have organized the system to allow that to contaminate the much more voluminous domestic wastewater solids.

You scratch your little green alien head with your little green alien paw and say, “Why do the people put up with this apparent insanity?  How DID they get here?”

It’s that tradition that our space travelers don’t know about.  The following quote from the 1983 World Health Organization book Sanitation and Disease pretty well encapsulates the situation:

“Those whose job is to select and design appropriate systems for the collection and treatment of sewage … must bear in mind that European and North American practices do not represent the zenith of scientific achievement, nor are they the product of a logical and rational process.  Rather, [they] are the product of history, a history that started about 100 years ago when little was known about the fundamental physics and chemistry of the subject and when practically no applicable microbiology had been discovered…. These practices are not especially clever, nor logical, nor completely effective—and it is not necessarily what would be done today if these same countries had the chance to start again.” [Emphasis added]

This quote dwells on the wastewater system, and this is the field of my expertise, so most of what I have to say [in the presentation] is focused on this portion of our water resources infrastructure.  But as I’ve just reviewed, and as our visionaries [other presenters at the conference] have shared with you these last two days, there may be reason to question water supply and stormwater management strategies as well.

As stated in the quote above, the form of the wastewater system infrastructure is largely the product of sanitary engineering tradition.  City populations were exploding, there was extreme squalor developing, and there was a growing awareness of the connection of these conditions to disease.  So the focus was on piping this stuff to that place we call “away”, the universal definition of which seems to be “no longer immediately noticeable by me”.

Only later, as it was seen that the discharge of raw wastes had transformed rivers into foul, open sewers was treatment at the end of the pipe considered.  I’ve read that there was, in fact, a rather intense debate around the beginning of [the 20th] century among water resources engineers whether it would be more “efficient” to treat wastewater before it was discharged, or for downstream users to suffer higher water treatment costs.

Fortunately, today we have a little more respect for other values provided by our lakes, streams and rivers, and treatment of wastewater prior to discharge is almost universally the norm in this country.  However, having recognized the need to do that, it seems we have never gone back and questioned that “pipe it away and dump it” tradition.  Not only do we seem compelled to pipe it away, we want to pipe as much of it to one place as we possibly can.  This centralized system is the largely unquestioned paradigm controlling the development of wastewater system infrastructure.

As our space travelers observed, if you take a hard look at the system of hardware that has developed from this tradition, there are a number of reasons to question why we continue to do things this way.  For one, we’re spending a whole lot of money just to move pollution from place to place.  That system of pipes and lift stations consumes the vast majority of the capital cost of a centralized system.  We’re also concentrating large flows through one pipe or lift station or treatment center, so by the very nature of the system, the consequences of almost any mishap are catastrophic.

Especially since the larger pipes typically run along the lowest terrain available—our riparian environments—we also create significant environmental disturbance when we install, upgrade or maintain the centralized collection system.

And we’re finally coming to realize that the so-called “waste” water is indeed a water resource that we could be utilizing for non-potable purposes to displace a great deal of demand for highly treated potable water.  We’ve found that, once we’ve piped this water “away”, it’s awfully expensive to pipe the recovered resource back to where it can be beneficially  used.

And if we don’t reuse the water, if we just continue to flush it into aquatic environments, the large point source discharges of “allowable pollution” are often problematic, urging the use of ever more expensive advanced treatment processes.

The centralized system also tends to impose a “one size fits all” management system onto a service area, regardless of local characteristics.  The attitude of this traditional paradigm seems to be, if you’re not on “the sewer”, you’re on your own.  So it is not very flexible, and thus not very responsive to land use decisions.

And any upgrades or major extensions of the service area typically entail large-scale projects with long lead times for planning and financing, so the system is also slow to respond to land use decisions.  In a dynamic development environment such as we have here in Central Texas, this can lead to some pretty sorry performance of the management system.

Well, if all these problems are so obvious, if this system is indeed “not especially clever, nor logical”, why have we stayed with this paradigm for so long?  It’s because of the institutional barriers that are arrayed against change.

In my view, the nature of the engineering business is the most problematic institutional barrier.  Billable hours are god.  So it’s really hard to muster much impetus to incorporate new methods and ideas unless the individual engineers go out and learn about these on their own.

That is, unless the firm can talk the client into funding its learning process.  But I’m sure you can see the obvious “image” problem this would create.  The firm has undoubtedly sold itself to the client as the people who can solve its problem, so how would it look if they said, “Hey, there’s some other ideas that ought to be entertained, but we need some hours in our contract to learn about them”?

The result is that most engineering firms are not proficient in anything except business as usual.  I’d venture to guess the percentage of firms that could design, say, effluent sewers or sand filter systems is pretty small.  And even fewer could actually visualize alternative management concepts in which these technologies would fit.  Because of this situation, most firms have a strong vested interest in seeing that their projects focus on the conventional management paradigm.

Added on to this, the sanitary engineering field is, rightfully so, rather conservative.  There are, after all, serious public health and environmental implications at stake here.  But this conservative nature results in any methods and strategies outside the prevailing paradigm, no matter how well justified, being very slow to be embraced.  In what other field, I wonder, is stout defense of the status quo at the expense of vigorously pursuing better and more economical ways of doing the job seen as the best way to maintain and expand your business?

One aspect of that conservatism that has often been used as an excuse for not pursuing alternative strategies is that it’s perceived as difficult to get them permitted through the regulatory agencies.  I don’t believe that’s as much of a problem as it once was.  The so-called alternative methods have been kicked around long enough now that many, if not most, regulatory agencies are at least open-minded about them. [Sadly, in the intervening 2 decades, that has not always been borne out.]

In fact, if there is an expectation that other methods and strategies may result in systems that are less costly, friendlier to the environment, and would have societal benefits, an obvious place from which to stimulate change are the regulatory and funding bureaucracies.  But these institutions tend to concentrate more on process than on substance. Then too, the people in these bureaucracies have been indoctrinated in the same tradition that holds sway among the engineers that submit plans to them.  So these bureaucracies tend to accept those plans without a whole lot of critical questioning about cost and resource efficiency. [As we are now seeing in places like Dripping Springs and Blanco.]

Financing is another significant institutional barrier.  Regardless of the true global costs of various options, institutional arrangements for financing projects are often highly biased toward traditional strategies.  Typically, one who wishes to investigate anything besides “the sewer” is largely on his own and is looking at paying for the ENTIRE management system.  If one hooks up to “the sewer”, on the other hand, the buy-in cost is often a small fraction of the total costs, with the operating entity financing the rest through bonds and grants.

Another significant barrier is the entities that operate the systems.  That’s easy to understand – these guys are immersed in making sure that their existing systems are being operated and maintained properly so they don’t get their butts in a crack.  And basic human nature is also at work here—people are comfortable with the familiar and fear the unknown.  If you go to these people and suggest that they should reorganize their management system and retrain their people to accommodate new methods and strategies – well, that’s not going to make the hit parade with many of them.  At least not without a concerted effort to educate them on how that would be better for the community they serve, and ultimately on down the line for them as well.

And that brings up education.  If education is the key to proliferating better ideas in this field, then perhaps what we have here is a massive failure of the educational system.  It is indeed true that, until fairly recently, engineers who work in this field had not been taught anything but the traditional methods and strategies in their university studies and continuing education courses.  But for many years now, opportunities to learn about other ways to skin this cat have been widely enough available that just about any firm that does a significant amount of wastewater system work could have become expert in other methods and strategies. [That this has not really happened in the intervening 2 decades speaks volumes about how massively the education system has indeed failed.]

And finally, system users are another group that must be addressed.  It can be reasonably argued that the user shouldn’t care how the system hardware is arranged as long as the system is “transparent” to him or her, if all he or she has to do is flush the toilet and pay a fee.  But there is an almost universal fear that proposals to implement “alternative” systems would be rejected by the people that would be served by them.  It seems to come across that any alternative system is “experimental” or a second-class option.  We have a situation right here, in the suburban area of Westlake Hills [which was planning to sewer parts of its jurisdiction at that time], where some citizens are opposed to an effluent sewer system.  Their attitude seems to be fairly well encapsulated by what a lady actually said to me one time when discussing the possibility of a decentralized wastewater system – “Why don’t we just pay more and get a real sewer system?” !!  Also, as long as some funding agency is willing to pony up the lion’s share of the cost, why should the users be particularly interested in assuring that the most cost effective option is implemented?

That’s a lot of reasons to stay “stuck”, isn’t it?  So where do we go from here?

Despite all these barriers to change, a paradigm shift is coming and things are beginning to change, albeit at a snail’s pace. [As we’ve seen in the intervening 2 decades, the pace has indeed been that of a very slow snail.]  I believe that eventually society will come to embrace a “decentralized concept” of management, an idea that I’ve been exploring and discussing since 1985.  That year, in fact, I obtained a permit from the state of Texas for what may have been the very first decentralized concept system ever permitted.  So much for the excuse that you can’t get these things through the regulators, huh?  Unfortunately, that project died in the development bust we had here in 86 and 87.

This decentralized concept will be the antithesis of the conventional, centralized management paradigm.  Under this new paradigm, we will focus on utilization of a resource rather than on disposal of a nuisance.  Rather than look for the most efficient way to make it “go away”, we will look for the most efficient way to reuse the water and the nutrients it contains.  In general, decentralization of the treatment system is the key to achieving this goal.

Decentralization will eliminate a majority of the expense of installing, upgrading and maintaining the far-flung centralized collection system, allowing a far higher percentage of society’s investment to be focused on removal of pollutants rather than on just moving it around, and on reusing these reclaimed water resources.

Decentralization will allow segregation of industrial flows.  Sludge can be classified by source and the biosolid product from “safe” sources will be more easily marketable.  I envision the use of septic tanks or hydroseives located at the source of wastewater generation to be the basic sludge production devices.  While the many dispersed sources of sludge creates a management challenge, timing of sludge handling is not critical with these technologies, and I believe that sludge handling will be less problematic than it is now at centralized plants.

Removal of settleable solids at the source of generation also means that conveyance facilities can be small diameter effluent sewers.  These are less costly to install and maintain, and they practically eliminate infiltration and inflow to the sewer system.  So besides eliminating the cost of interceptor mains and lift stations, the decentralized concept also entails a local collection system that is more economical and eliminates the pervasive problem of high wet weather flows.  Typically, the savings in the local collection system by itself will more than pay for the septic tanks required to allow the use of effluent sewers.

To assure that operations and maintenance of many dispersed treatment facilities is not an untenable problem, treatment technologies will be chosen that are inherently low maintenance.  The small scale of the system will make it cost efficient to design in safeguards against catastrophic failure, and modern remote sensing capabilities will allow the operator to readily monitor the progress of chronic problems.  In short, the treatment system will be far more “fail-safe” than conventional plants, which typically employ the inherently unstable activated sludge technology, and so they won’t need to be placed so far “away” or be watched so continuously.

Some think that newer methods like membrane technology will be the best choice for dispersed treatment systems, and these methods may have a place, but I believe that the workhorse technology of decentralized concept systems will be updated versions of an ancient art – sand filtration.

This technology offers inherent stability, is easy to monitor and control, and, on the rare occasions it’s needed, can be serviced and put back in action in short order.  It’s also capable of producing near-potable quality water, appropriate for a variety of beneficial reuse applications.  Finally, it is a technology that is actually much MORE amenable to use in small-scale treatment centers than in larger plants.

Reuse opportunities that can be entertained without too much institutional resistance are subsurface drip irrigation of any greenspace, surface irrigation of controlled areas, flush water supply to non-residential buildings, and industrial processes that are not highly sensitive to source water quality, or that already employ point of use treatment in any case.  Perhaps after demonstrating that we can indeed control the system and consistently and reliably produce a near-potable quality effluent, we might expand our options to include surface irrigation of uncontrolled areas, flush water supply in residential buildings, cooling tower makeup supply, a wider variety of industrial processes, and perhaps even laundry water supply.

While I see the decentralized concept as where we’re headed, of course we’re not going to abandon the prevailing paradigm and adopt a new one overnight, regardless of how unclever or illogical the prevailing paradigm may seem – society just doesn’t operate like that.  But we do need to begin critically examining our opportunities to move in that direction.

I’ll close with an example of such an opportunity.  There was an article in the local paper a couple weeks ago about the Austin city government’s efforts to direct growth eastward, to what is termed the “Desired Development Zone”.  A problem pointed out by a developer who is planning a project out there is the need to expand and upgrade the city’s water and sewer system in that area in order to handle the growth.  It was reported that this developer needs $10 million worth of infrastructure improvements.

I spoke with [then Assistant City Manager] Toby Futrell after her talk [at the conference] yesterday, and she confirmed that the City is not considering decentralized management as a possibility anywhere in the Desired Development Zone.  Now if we so blindly follow the traditional paradigm, if we simply settle for the status quo, that will be another $10 million invested in piping it “away”.  Another $10 million invested in adding to the problem of long-term regional water supply shortages, another $10 million invested in moving pollution from place to place, in exacerbating point source pollution, and in adding to the biosolids reuse problem.  But in this case we have a somewhat clean slate.  Here there hasn’t been decades of investment in the traditional paradigm that must be respected.  Here we have the opportunity to consider the costs and benefits of building in a new paradigm from the beginning.

This is how we need to start thinking EVERY time a significant investment in our water resources infrastructure system is considered.  The problems are not technological, rather a matter of mustering the political and managerial will to break through the institutional barriers.  We can invest in the past, or we can invest in the future.  The choice is ours.

 

If we just would use global cost accounting …

Posted October 20, 2017 by waterbloguer
Categories: Uncategorized

I was chatting with a friend awhile back, and he asked me what projects I was working on. I told him about a meeting I’d just had with some folks proposing to develop a piece of land near Bulverde, just northwest of San Antonio, an area in which water supply is a critical issue. My reason for talking with these folks was to offer a sustainable water management concept to serve their development, entailing the strategies we have been discussing in this blog:

  • maximizing rainwater harvesting for both water supply and as a component of stormwater management;
  • a decentralized concept “waste” water system focusing on practically maximizing the resource value of this water, mainly for irrigation supply, but in this case perhaps also for toilet flush water supply in the commercial and institutional buildings planned for this project; and
  • an LID/green infrastructure stormwater management system that would hold much of the increased runoff caused by development on the land rather than “efficiently” draining it “away”.

The developers’ major focus in this particular meeting was the wastewater system. They wanted to understand the fiscal implications of pursuing the decentralized concept strategy vs. connecting to an area-wide conventional wastewater system, which would entail a 13,000-foot line to be extended to this property (and, I presume, one or more lift stations, given the topography of this area). But they also seemed very leery of the “hassle factor” of dealing with the Texas Commission on Environmental Quality (TCEQ) to permit a stand-alone decentralized concept system for their development. They perceived this permitting process would not be as “clean” and “easy” of an institutional process as “simply” joining the existing conventional centralized system. So the impression I got was that the cost implications would have to lean rather starkly in favor of the decentralized concept strategy if they were going to even investigate what permitting and running it may entail.

And this is where the tale becomes rather frustrating. As I related to my friend, one of the guys did a “back of the envelope” calculation of the cost of the 13,000-foot connection to the conventional system, which came out to be very similar to the rough ballpark cost I’d offered for the decentralized concept strategy, given the number of connections they were projecting. It was unclear if his estimate included anything but the connection line. It appeared not because he was just multiplying a cost per foot figure – offered by an engineer connected to the conventional wastewater system, I presume – times the length of the line.

As I told my friend, I began to identify costs we would need to include if we were to arrive at an “apples to apples” comparison with the decentralized concept strategy. That approach serves up a complete wastewater system – collection, treatment and reuse – while that 13,000-foot line by itself is only a partial collection system, not including all the internal collection lines (and lift stations, if needed) within the development. It also does not include connection fees, the buy-in to the centralized treatment plant capacity and any system improvements needed between the point of connection of this project to the centralized collection system and the treatment plant. That charge would likely accrue not to these developers, but to the builders, as each building or neighborhood connects to the centralized system.

Then I noted to my friend – I was really on my soapbox now – that their accounting also totally ignored the value of the water resource embodied in the “waste” water. And the eventual cost of upgrading/expanding the area’s water supply system, driven by the need to provide all the irrigation (and toilet flushing?) water for this project – and by extension for many other projects in this fast developing area – if all that “waste” water were dumped down the drain instead of reused to defray those demands. Both the costs of upgrading the water system facilities and of accessing new water supply to run through them – which in this area gets us into that whole issue of raiding remote aquifers that we’ve looked at in a previous post.

Then too, being a distributed system, it may be quite practical to install the decentralized concept system in phases, matched to the level of imminent development. So a considerable portion of the ultimate total cost of that whole system might be put off till later, saving the “time value” of the money not expended up front to get the development started. Unlikely the developers will factor those savings into their decision.

All in all, I told my friend, from a global perspective, there are a lot of cost factors that “should” be considered to get to that “apples to apples” comparison. But it is to be expected that at least some of them will not be considered as these developers make their fiscal comparison. And that is because folks don’t look to a global cost accounting when making those decisions, rather they only look at the costs that they would directly bear themselves, fairly immediately. Thus these guys’ preoccupation with that 13,000-foot extension, to the apparent exclusion of those other cost factors, as that’s the very visible immediate cost they’d bear to be able to actuate their development.

There’s also the “hassle factor” beyond the TCEQ permitting process. These developers are very leery of having to set up an entity that would handle on-going operations, maintenance and compliance monitoring of a stand-alone decentralized concept system. They most definitely would not want to be involved in running any such operation themselves; indeed, few if any developers would be. That is not their business, and they quite understandably don’t want to be bogged down in it.

A solution to that problem would be for the owner-operator of the area-wide centralized system, the Guadalupe-Blanco River Authority (GBRA), to become the owner-operator of distributed systems within this area. What GBRA is actually selling is a service, not a connection to a specific type of system. That just happens to be the manner in which they are presently organized. GBRA could just as well obtain revenue from operating and maintaining distributed systems. This concept has in fact been posed to them a few times, dating back a couple decades. But GBRA appears stuck in its mental model, always has been and apparently still remains so invested in its current business model, operating the centralized system, that it will not entertain whether it would be more globally cost efficient to provide that service by other means. This too warps the perspective of the developers, who perceive that under the centralized plan they can “just” install their collection lines, pay their fees, and then they are out of the wastewater business. While if they go with the decentralized concept strategy, no matter how much more globally cost efficient it may be, they would have to take on duties they’d rather not get into – organizing, if not actively running, a wastewater system.

This situation facing these developers and that wastewater system operator is a ubiquitous problem in our society. As I’ve noted on this blog in another context, “Society has not figured out how to send to those who incur the first costs the signal sent by the global life-cycle costs. The result is that choices are made which may well serve the short-term interests of those who bear those first costs but poorly serve the long-term best interests of society.” That may be exactly the outcome here.

As was noted in “Motherless in Bee Cave”, everyone is invested in their “deal of the moment”, focused on what they perceive best serves their bottom lines in the short term. So we have this situation where society would be paying more to degrade the cause of sustainable water than, if it followed the lead of global cost accounting, it could be paying to bolster sustainable water, saving money while saving water. How we can “get around” all these deals of the moment and make those global evaluations the basis for decisions on water management is a mystery. One of many this society must solve if it is to remain sustainable.

 

Tom Brady’s Complaint

Posted December 2, 2016 by waterbloguer
Categories: Uncategorized

The Dripping Springs wastewater discharge permit is now before the Texas Commission on Environmental Quality (TCEQ), which will determine whether or not to grant the permit and allow discharge into Onion Creek, an environmentally sensitive Hill Country stream. The issues with that course of action have been discussed here, here, and here, reviewing and highlighting the many fiscal, societal and environmental factors which rationally would be brought to bear on such a decision. If TCEQ holds to form, however, very little of that will actually have any bearing on the decision. Rather, the decision would hinge pretty exclusively on whether Dripping Springs has conformed to a process and has presented a plan of action that TCEQ deems would meet the wastewater treatment standards that TCEQ has chosen to impose. Standards which seem to be limited by that process, and so have been called to question as being equal to protecting water quality in Onion Creek.

Which takes us to Tom Brady’s complaint. The NFL succeeded in depriving the New England Patriots quarterback of four games out of his career pretty much completely on the basis of “process”. Similarly to the manner in which TCEQ will review the Dripping Springs permit, the legal review of Brady’s case centered on whether the process fell within the nominal bounds of the agreement between the NFL and the players’ association. The NFL was never required to produce any objective proof that what Brady was accused of participating in – underinflating footballs he used in a playoff game – ever even happened! (Anyone who actually understands the Ideal Gas Law will attest to that.) Thus Tom Brady’s complaint is that he was “judged” and “convicted” with no proof of wrong-doing having been required by the controlling institutions empowered to rule on the propriety of the NFL’s decision.

Before proceeding, I hasten to note that this is not a “fandom” thing. Indeed, anyone who knows me knows I’m a diehard Green Bay Packers fan, no fan of the Patriots. While I respect Brady’s abilities and accomplishments, this is not about the man, this is about the level at which we allow our society to “function”.

To the point here. The “machinery” of society sits still for this matter being executed at the level of “process”, pretty much devoid of substance, in an arena so central to the American psyche as football. What hope is there, then, for meaningful pushback against similarly ignoring the actual impacts on society, subsuming them to “process”, in an arena that most people don’t want to ever even think about – what happens to their wastewater after they flush the toilet?

The “Tom Brady’s complaint” of anyone who has chosen to consider the actual fiscal, societal and environmental factors surrounding Dripping Springs’ approach to wastewater management is that the controlling institutions who will permit that strategy will not take most of that into account. As noted, the decision will be based only on conformance to a “process”, rather than on a consideration of actual causes, effects, and outcomes. Thus, just as Tom Brady was afforded no forum for a consideration of the factual basis for what he was accused of participating in, the deflation of footballs, local society has no forum for the review of those fiscal, societal and environmental impacts, no way to bring them to light, to be prudently and factually considered.

In particular, TCEQ will absolutely not require any showing that the infrastructure model Dripping Springs is dead set on pursuing is the “best” way for them to proceed, by any measure. That infrastructure model – a conventional centralized wastewater system, routing flows from miles around to one point – is the whole predicate for even considering a discharge, so in a way is the whole problem here. Indeed, that model entails a number of fiscal, societal and environmental liabilities, as have been reviewed here, so reconsidering that infrastructure model could offer many benefits to Dripping Springs and its citizens and development clients.

But the TCEQ process allows Dripping Springs to utterly ignore all those fiscal, societal and environmental factors, that a thinking person would consider central to any such far-reaching decision. And indeed it is far-reaching. Once Dripping Springs commits to extending and perpetuating the prevailing 19th century centralized infrastructure model, that will cement into place for generations to come a mode of management that will hamstring efforts to move local society toward sustainable water. It will instead “institutionalize” the low water use efficiency that is characteristic of that 19th century model.

It appears that all the machinery of society will sit blandly by and allow this “triumph” of process over substance. No one appears much interested in lobbying TCEQ to broaden the scope of what would be deemed important to consider. Not downstream interests, not the affected citizenry – who will be financing the city’s overpriced strategy – and not the “leadership” of society, such as local legislators and city and county officials.

So, being empowered to blindly follow their mental model, never being even asked, much less compelled, to question its underpinning – that is, to actually examine those fiscal, societal and environmental factors – Dripping Springs is being allowed to close out a major avenue to deep conservation. Recall that is defined (here) as water use efficiency that is “built in” to the water infrastructure model, that will deliver that efficiency just as a matter of course, year after year. Losing this opportunity to attain deep conservation will be a disservice to local and regional society.

Again, as long as all concerned simply sit by and allow these matters to be considered solely on the basis of a “process” that ignores the underlying facts on the ground, we will all suffer Tom Brady’s complaint – a “sentence”, in this case on society, will be carried out without ever having considered the things that really matter. In Brady’s case, whether any “crime” actually happened; in ours, whether we will proceed to develop in a manner that moves us ever further away from sustainable water – and be more costly and more environmentally problematic.

With apologies to Steve Earle, I guess this is just America V 6.0, “It’s the best that we can do.”