The Croton Watershed:
by Alexander DeLuca, M.D., firstname.lastname@example.org. Originally posted: February 19, 2003; Most recently revised: May 14, 2005. This paper was written as an assignment for the Course P6300: Environment Sciences, Columbia University Mailman School of Public Health, Professor Brandt-Rauf, email@example.com
The people who live in the NYC watershed rate clean drinking water
as the most important social problem and have demonstrated a willingness to
support governmental efforts to protect and enhance it. In 1999, EMPACT, an
interagency Presidential Initiative, conducted a survey of the general public.
Among the findings for Region 2, which includes the NYC watershed:
And the citizenry are highly organized. Locally, the Bronx Council for
Quality and the Croton Watershed Clean Water Coalition (CWCWC) have taken the
lead in advocating for Croton watershed maintenance and restoration programs,
and these are backed by diverse groups including block and community
associations, local and regional chapters of the Audubon Society, Trout
Unlimited, the Sierra Club, and Riverkeeper, among others.
And the citizenry are highly organized. Locally, the Bronx Council for Environmental Quality and the Croton Watershed Clean Water Coalition (CWCWC) have taken the lead in advocating for Croton watershed maintenance and restoration programs, and these are backed by diverse groups including block and community associations, local and regional chapters of the Audubon Society, Trout Unlimited, the Sierra Club, and Riverkeeper, among others.
The federal government is also committed to clean drinking water, and it has developed elaborate policies that it aggressively pursues. The Safe Water Drinking Act of 1974 forms the basis of federal regulation of public water systems. In 1989 the EPA promulgated the Surface Water Treatment Rules (SWTR) to limit the publics exposure to waterborne pathogens and make it’s Total Coliform Rule more stringent. [Kramer, 1996]
The State has likewise demonstrated that protection of the watershed is a top priority. On 5/23/2002 the Army Corps of Engineers, concluding a process begun by Governor Pataki, officially designated all waters east of the Hudson River as Critical Resource Waters (CRW). CRW status compels attention to source protection and strengthens enforcement of regulations already in place. The result is that stricter standards must be met prior to any development activity in the watershed. [CWCWC, 2002]
Finally, the City, after manifesting little enthusiasm under Mayor
Giuliani for the difficult political and legal work necessary to protect the
watershed, has become fully involved. It was encouraged, perhaps, by the
necessity of dealing with a law suit brought against it by the EPA in 1997 to
force the building of a filtration system for the watershed. The settlement
was a City, State, and Federal "Watershed Agreement" in which the
NYC Department of Environmental Protection (NYCDEP) agreed to build a
filtration plant for the Croton watershed. Since then the NYCDEP has embarked
on a plan to purchase land within the Catskill and Delaware systems to avoid
having to filter them; perhaps wrongly, it did not seek a filtration waiver
for the Croton system at that time.
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"Water quality data analysis shows that fecal coliform levels, turbidity and disinfectant byproduct levels are all within acceptable limits. NYCDEP has never incurred a monthly maximum contaminant level violation… [and] monitoring has shown that adequate disinfectant concentrations are being maintained." [EPA, 2000]In essence, the Rules do not admit the possibility of a community stewardship that protects and enhances water quality. They represent a failure to understand that the health of a watershed is determined not by ownership, per se, but rather by how the land is managed, how land usage is prioritized, and toward what end.
Filtration systems are complex, centralized, industrial plants that require continuous maintenance and monitoring. Though promoted specifically to limit exposure to infectious agents, such plants cannot completely eliminate water borne disease outbreaks (WBDOs). First, not all pathogens are susceptible to current detection and treatment technology. Giardia and enteric pathogens are the usual targets for determining adequacy of treatment, but other common pathogens are not routinely or easily discovered. The most important such is Cryptosporida, which was found to be more common than Shigella and almost as common as Salmonella in a two-year prospective study conducted in 1985. [Meinhardt, 1996] None of the technologies widely in use is completely effective at inactivating and removing Cryptosporidum oocysts. "[Even] when multiple barriers are operating efficiently, oocysts may break through a treatment system..." [Meinhardt, 1996]
And when treatment systems fail, they can become a contributing factor in WBDOs. Filtration plants concentrate the pathogens that they remove, and can become a reservoir in the life cycle of the pathogen. [Meinhardt, 1996] If operational lapses or frank filtration failure occurs, the results can be dramatic. For example, in 1967 a WBDO of some 13,000 cases occurred in Georgia in a filtered water supply due to "operational irregularities" in the filtration system; Cryptosporidium oocytes were detected in 38% of the stool specimens associated with this outbreak. In 1993 Wisconsin experienced 800 confirmed cases of cryptosporidiosis and an estimated additional 400,000 cases of diarrhea due to inadequate removal of oocysts by the coagulation/filtration process in use. [Meinhardt, 1996]
Finally, there are serious social and political problems with centralized filtration water treatment systems. As large and complex industrial plants that take many years to build and which operate in close proximity to the communities they serve, they arouse NIMBYism and are difficult to site. Cost is another problem, especially in the current environment of massive City and State budget deficits. But perhaps the most important negative and far-reaching social consequence is subtler. Compared to the dispersed installations and varied practices employed in the soil/watershed alternative (SWA), centralized filtration systems are disempowering by their very nature. Rather than collectively sharing responsibility for nurturing a watershed, the citizenry tend to rely passively on an industrial plant to assure quality drinking water.
The Soil/Watershed Alternative
The SWA is a collection of decentralized, redundant, low-cost, mostly landscape-based installations placed throughout the watershed. These are designed to collectively maximize the amount of rainwater and runoff that enter the soil, and to increase both the hydroperiod contact time and filter contact time. [Mankiewicz, 1998] The strategy is to connect street and land runoff with streams, wetlands, forests and meadows and to allow nature to filter and biogeochemically neutralize pathogens and chemical toxins. Such an approach depends on intensive and continuous monitoring of environmental markers and water quality, rigorous policing of business and household water use and waste practices, and vigorous enforcement of environmental regulations. Resource management expertise, adequate staffing levels, sufficient alignment of goals, and stakeholder leadership skills are necessary for successful collaborative watershed management. [Henly, 2002] This level of community involvement and collaboration seems daunting in the abstract, and is considered by some a drawback of this approach.
I would argue, however, that this combination of a common goal, scientific and technical expertise, and capable stakeholder groups with experience working with each other exists right now in the Croton region. The NYC watershed is the largest, unfiltered, surface water system in the nation, and it sits in a densely populated and rapidly growing area. We have a historic opportunity to demonstrate that sustainable development, development coexisting with watershed protection and enhancement, is achievable through collaborative resource management.
1 EMPACT (2000). Local Urban Environmental Issues Study of 86 Metropolitan
Areas - Region 2. Environmental Protection Agency. http://www.epa.gov/EMPACT/techtransfer/region2.pdf
(accessed February 14, 2003).