The issue of fish consumption rates is something Washington has been wrestling with for years, but is an issue that has received mainstream media coverage only in the past year or so. I think it still is an issue that seems largely esoteric to many–frankly, it is a complex issue from a science, policy, and legal perspective, so it doesn’t surprise me that the average citizen’s eyes would glaze over if exposed to the topic. But, the latest study from the Association of Washington Business, in partnership with the Association of Washington Cities and the Washington State Association of Counties, really drives home the point that everyone in Washington should be paying attention to this issue–for the simple reason that it may result in alarming increases to the utility bills of all Washington residents.
For those of you that haven’t been tracking the fish consumption debate, it involves the adjustment of Washington’s water quality criteria to take into account higher fish consumption rates of certain populations in Washington. For context, the current water quality criteria for toxics are based on a fish consumption rate of 6.5 grams per day. The new rates being contemplated are around 175 grams per day. Because fish consumption rate is one of the factors in calculating water quality criteria for the protection of human health, an increase in consumption rate results in a decrease in water quality criteria, so going from 6.5 grams per day to 175 grams per day can lead to a dramatic decrease in a particular water quality criterion, resulting in criteria that are much more stringent, and potentially unattainable.
The AWB study attempts to quantify–in dollar terms and in other ways–the impacts these more stringent criteria will have on wastewater treatment, and, ultimately, utility rates.
The bottom line: the study projects that an average utility bill in Washington could go up by $200/month as municipalities attempt to achieve the more stringent water quality criteria, and those dollars may be spent in a futile attempt to attain the unattainable.
Here are my thoughts on the AWB study:
From a science/law/policy perspective, I found this study fascinating, because it translates the relatively esoteric issue of fish consumption rates into meaningful and accessible information that adds tangible context to a complex policy decision. The study looked at four toxic compounds: arsenic, mercury, benzo(a)pyrene (BAP), and PCBs. These four toxics are relatively representative of the range of toxic substances implicated in the pending revisions to Washington’s water quality criteria, and are a useful sub-set of those toxics because they represent both metals and organics, and are toxics derived from a variety of sources.
The study derived water quality criteria assuming a fish consumption rate of 175 grams per day, and found that, for three of the four toxics, there was no available treatment technology that can achieve the projected revised water quality criteria. One of those toxics, BAP, was present in levels of influent and effluent below the projected water quality criteria, and that compound is the one of the four where it was possible to meet the projected revised water quality criteria. Not surprising given its low presence in municipal wastewater. The other three were present in influent above the projected revised water quality criteria, and a review of performance of available technologies indicated the revised criteria could not be met for these three toxics. One of the main challenges in treating wastewater to these low levels is that you need to employ different technologies for different toxics, and therefore need to employ secondary treatment strategies that combine technologies like microfiltration membranes, reverse osmosis, and granulated activated carbon to address different toxics with different chemical properties.
The inability to treat municipal wastewater to achieve the low levels of toxics wasn’t very surprising to me. We’re talking proposed water quality criteria not in parts per million (10^-6), but parts per billion (10^-9), or parts per trillion (10^-12). For those of you having trouble visualizing a part per million, think one drop of water in a bathtub. One part per billion? Think one drop of water in five Olympic-sized pools. One part per trillion? We’re now up to one drop of water in five thousand Olympic-sized pools. (Just for kicks, the next lowest concentration, parts per quadrillion (10^-16) is about thirty drops of water in all of Puget Sound, assuming a volume of 170 cubic kilometers).
We’re really in the weeds with some of these contaminants in terms of concentrations that will need to be attained under the revised criteria, and are far beyond the big effluent reductions seen in the first couple of decades after the Clean Water Act was enacted and implemented.
What happens when you try and achieve lower and lower standards? You have to spend more and more money to make a smaller and smaller incremental gain. The AWB study goes into the costs to try and achieve those criteria. For a 5 million gallon-per-day treatment plant (an average size municipal wastewater treatment facility) the study projects a cost increase of $12 per gallon of treatment capacity to integrate the secondary treatment technologies mentioned above. That is at least $60 million more for capital costs alone. Smaller plants are more expensive on a per gallon basis, larger plants less, and the study recognizes there will be variability in those costs based on many site-specific factors, so this $60 million cost is a ballpark estimate. This capital cost comes with a $5 million to $15 million increase in annual operating costs. And, consistent with the concept that you have diminishing returns on dollars invested as concentrations in effluents get lower and lower, the cost to remove one pound of a particular contaminant over a twenty-five year period is remarkable. For PCBs, that cost in net present value is $290 million, for BAP, $120 million, and for mercury, almost $30 million.
In addition, the study notes that the implementation of these treatment technologies, besides not achieving the goals being set, may result in significantly negative impacts to overall sustainability goals set by municipalities. For instance, reverse osmosis is incredibly energy-intensive, and implementing that technology seems to be contrary to many municipal energy-efficiency initiatives in place in Washington. Coming with that energy demand is potential greenhouse gas emissions–projected to more than double under these treatment scenarios. Reverse osmosis also generates salty brines that need proper handling and disposal, and other treatment technologies generate sludges and wastes that may have to be disposed of as hazardous waste.
All of the above should be food for thought for Ecology and elected officials, and the AWB study nicely frames some of the issues that law and policy makers need to digest as the fish consumption debate continues. It will be interesting if other dischargers follow suit. I would like to see similar studies that look at technologies that apply to other types of dischargers–I bet this theme of unattainability at great cost is something that is present for the vast majority of dischargers in Washington, municipal or otherwise.