New York's Kensico and West Branch Reservoirs Confront Intensified Development
Top of Report
THE ENDANGERED KENSICO WATERSHED
A. THE KENSICO RESERVOIR AND ITS IMPORTANCE
The Kensico Reservoir is located in central Westchester County, about three miles north of White Plains and 15 miles north of New York City. It consists of a western "main basin" and an eastern Rye Lake portion, with water flowing freely between the two. Although Kensico was formed by the damming of the Bronx River in 1915, the reservoir receives most of its water from two huge aqueducts that transport water from the city's six West-of-Hudson reservoirs in the Catskill and Delaware system watersheds. (See Map 2.) The Kensico Reservoir, which holds 30.6 billion gallons at full capacity, is surrounded by its own, comparatively small, watershed of approximately 10 square miles. Waters flowing into the reservoir from these surrounding lands are responsible for most of the pollution threats facing Kensico today.
As noted above, Kensico plays a central role in delivering water to nearly nine million downstate residents. This reservoir is the last stop for roughly 1.3 billion gallons a day of Catskill and Delaware system waters. These waters are usually held in Kensico for 15 to 25 days before heading into the much smaller Hillview Reservoir in Yonkers for distribution throughout the five boroughs. (This 15 to 25 day period provides a final opportunity for settling out impurities, including solids and microorganisms.) Water is tested as it leaves Kensico for the city's distribution network and must meet federal water quality standards if the city is to avoid building a filtration plant to treat water from the Catskill and Delaware system reservoirs. During normal operations of the city's intricate water supply system, roughly 90% of the water consumed in New York City flows through the all-important Kensico Reservoir.
B. THE KENSICO WATERSHED FACES INTENSIFYING DEVELOPMENT
The 9.9 square miles of land surrounding Kensico make up its small watershed, a total of about 6,000 acres. This includes portions of the towns of Harrison, Mount Pleasant, North Castle, New Castle, and Greenwich, Connecticut. As described below, this watershed has experienced accelerated commercial and residential growth in recent years. With about 1,950 dwellings and 5,500 residents, Kensico is already the most densely populated watershed in the Catskill/Delaware system. According to 1997 city data, land use in the Kensico watershed is approximately 30 percent residential and 20 percent industrial or commercial. (See Table 1.) In contrast, other unfiltered watersheds, such as those serving the cities of Seattle, Portland, Oregon, and San Francisco, are virtually free from residential or commercial development.
Table 1. Kensico Watershed Land Use
|Industrial/Commercial/Paved||2.0 mi.||1260 acres||20% of land area|
|Open Space||3.9||2436 acres||38.5%|
|Source: Adapted from NYCDEP Kensico Watershed Study, July 1997|
During the 1990s and up to the present, portions of the Kensico watershed have experienced a development boom. Over the last decade, several hundred acres of undeveloped land in the Kensico watershed have been lost to developers. In total, over a dozen significant commercial and residential development projects have been completed or are now advancing in this 10 square mile watershed. Among the largest projects, as of November 1998, were the following:
- IBM - On part of its 451 acre site, construction of a new 283,500 sq. ft. headquarters building , including parking for 850 vehicles. The former 420,000 sq. ft. headquarters will be renovated to house 1,100 employees of the IBM Credit Corp. A third facility, the IBM Learning Center (130,000 sq. ft.), is expanding its parking area to accommodate a total of 429 vehicles.
- Swiss Re America Corporate Headquarters - A 360,000 sq. ft. office complex is under construction on a 127 acre site, with parking for 1,029 vehicles. Buildings are being located as close as 1,000 feet from the reservoir itself. The North Castle Planning Board has given conceptual approval for additional development of 360,000 sq. ft. of office space at this site.
- Municipal Bond Investors Assurance Corporation (MBIA) Headquarters - Expansion of existing facility from 160,000 sq. ft. to 235,000 sq. ft. is under construction next to New York City buffer land. An additional parking structure is being built immediately adjacent to city buffer land; total on-site parking will then reach 678 vehicles. The MBIA headquarters land is 15.7 acres, and the company has expressed interest in purchasing adjacent residential parcels.
- Whippoorwill Hills - A 135 lot development of one- and two-family houses and a recreation center is under construction on 82 acres.
- Traveler's Conference Center - Recent development of a 42,000 sq. ft. executive conference center on a 26.6 acre site, with parking for 44 vehicles; Traveler's is now proposing to build a 30,000 sq. ft. accessory building, with parking for an additional 80 cars.
Other significant projects recently completed, under construction, or now on the drawing boards in the Kensico watershed include:
- General Electric Hangar at Westchester Airport - 65,000 sq. ft. hangar, 35,000 sq. ft. of office space, 100,000 sq. ft. airplane ramp and parking for 70 vehicles.
- Whippoorwill Ridge - Recently completed development of 50-60 individual and multifamily units on a 24 acre parcel.
- Inglenook Subdivision - 10 lot subdivision on 20 acres.
- Whippoorwill Heights Subdivision Section II - Most recent section of development that has been ongoing for many years. This section includes seven houses on 21 sloping acres.
- Chiselhurst - Proposed residential development on more than 100 acres, on a parcel including two lakes and several streams that are part of the headwaters of the Kensico Reservoir.
Emblematic of the development pressures now intensifying in portions of the Kensico watershed is the proposed roadway expansion of Routes 22 and 120 on the eastern side of the watershed, in the immediate vicinity of the Rye Lake portion of the Kensico Reservoir. Under a proposal advanced in 1997, the New York State Department of Transportation ("DOT") intends to widen a 1.2 mile stretch of Route 120 from a hilly, winding two lane country road to a four lane roadway, and to expand a stretch of Route 22 (with one additional traffic lane, two paved shoulder lanes and a paved median) in a location where the roadway is as close as 20 feet from the reservoir. This proposal is troubling for two reasons: (1) it will convert acres of green lands to impervious surfaces and increase stormwater run-off in one of the most sensitive watershed areas; and (2) it will encourage additional auto travel along the edge of the reservoir and lead to ancillary development in the watershed, attracting additional pollution sources.
Only after several elected officials from Westchester and New York City joined environmentalists in objecting, was this project placed on temporary hold by the state DOT. But with modifications to capture some highway run-off, this roadway expansion project is expected to regain momentum in 1999. Indeed, New York City is apparently cooperating with the DOT by providing the use of watershed land to facilitate this project. Unless the city reverses course and opposes the Route 22 expansion, or the state DOT is over-ruled by the Governor in his role as protector of the integrity of the watershed, blacktop and concrete for this extraordinarily shortsighted project will be poured in the near future.
Indeed, development pressures in the Kensico watershed are likely to continue well into the next decade. DEP has projected significant new development between now and 2010 on large tracts of undeveloped land, especially in the towns of New Castle and North Castle, within Kensico's fragile watershed. In 1995, this growth was projected to add more than 422 houses, dramatically increasing the number of residential units in the Kensico watershed by 22 percent. Office use was expected to jump by as much as 33 percent, and significant growth in ancillary businesses (gas stations, banks, restaurants) was also anticipated. A more recent draft report estimated that 847,000 square feet of office/commercial development could easily occur in the Route 120 corridor of the watershed under current zoning. Such development in the small and fragile Kensico watershed poses a serious challenge to the idea of relying on the Kensico Reservoir to supply high quality unfiltered drinking water in future decades.
C. KENSICO'S WATERSHED DEVELOPMENT INCREASES POLLUTION RUNOFF
A major threat to watersheds like Kensico -- and one that is exacerbated by ill-planned development -- is pollution runoff. This hazard, frequently called stormwater runoff, results when rain or melting snow races downhill into a reservoir or stream that feeds into a reservoir, sweeping top soils, pesticides, fertilizers, human and animal waste products, as well as roadway oil, particulates and salts along in its flow. The problem of stormwater runoff is and will always be a major threat to Kensico. But the greater the amount of watershed lands converted from their undeveloped, vegetated condition into residential subdivisions, office headquarters, parking lots and other impervious surfaces, the greater the problem of pollution runoff will become.
Pollution runoff is now a well recognized threat in the Kensico waters. With many rolling hills and an average slope of 10%, Kensico lands allow stormwater to flow quickly through this watershed -- making it more likely that the runoff will carry contaminants into the reservoir before they have a chance to settle or filter out naturally. This is especially true in portions of the watershed where development has already altered or eliminated the natural vegetation that would normally slow the runoff flow. In fact, as a result of previous and recently completed development, the amount of impervious surfaces (parking lots, roadways and other paved structures) has increased to a troubling degree in portions of the Kensico watershed. Several sub-basins have already been identified by DEP as having more than 40 percent impervious surface, and more than half of all Kensico land is in sub-basins that are over 10 percent impervious -- a figure that experts identify as a threshold at which degradation of streams first occurs.
An example of how local runoff can have significant effects on the quality of water in the Kensico watershed is the Malcolm Brook sub-basin. Malcolm Brook is a small stream that drains into the west side of the Kensico Reservoir. The Malcolm Brook sub-basin is 88 percent developed, predominantly office space and medium density housing. Over 40 percent of its land is impervious. DEP monitoring data from 1995 showed that Malcolm Brook was consistently contributing high levels of fecal coliforms to the Kensico, had the highest turbidity and total suspended solids values (of Kensico tributaries), and was contributing Giardia cysts and Cryptosporidium oocysts to the reservoir. As discussed below, the city is trying to manage this pollution and keep it from entering Kensico's effluent chamber (where water exits the reservoir for transport to New York City). Still, there is little being done to keep more pristine sub-basins from becoming as paved over as Malcolm Brook. Indeed, DEP has reported that by 2010, "[w]ith a projected increase in impervious surfaces due to real estate development, the future turbidity inputs to the reservoir are predicted to increase by 26% and FCB [fecal coliform bacteria] inputs are predicted to increase by 33%." To address those projected increases, the city plans to adopt "best management practices" (BMPs), such as runoff detention basins, to contain much of this pollution. Experts believe, however, that even with BMPs, when more than 30 percent of a watershed is covered with impervious surfaces, stream degradation becomes unavoidable.
D. THREATS FROM INTENSIFIED DEVELOPMENT IN THE KENSICO WATERSHED
Fortunately, water leaving the Kensico Reservoir today still meets state and federal water quality standards. But that fact does not tell the whole story. For one thing, if Kensico water tests actually revealed violations of health standards, the city could well be pressed to advance plans for multibillion dollar filtration facilities for the Catskill and Delaware water supplies. Moreover, once construction of a multibillion dollar filtration plant became imminent, the task of eliminating pollution sources and restoring the Kensico watershed ecology would become far more difficult, if not impossible, from a practical and political standpoint. Although water quality standards are not now being violated, there are warning signs in the Kensico watershed that preventive steps to protect water quality and forestall a filtration order must now be taken. We identify four such warning signs in the paragraphs below.
(i) Fecal coliform bacteria
One threat to Kensico water quality is fecal coliform bacteria. Fecal coliform bacteria, products of human and animal waste, are an important indicator of water quality; their presence suggests that other disease-causing organisms found in feces may also be present. The city is not now violating fecal coliform levels at the point which Kensico Reservoir water enters the distribution system. But, in recent years elevated fecal coliform bacteria levels have occasionally been recorded in Kensico and its tributaries.
In the early 1990's, coliform bacteria exceedances at Kensico were traced to the feces of water fowl, and DEP implemented a program to chase the suspected geese and gulls away from the reservoir. Historically, however, while the streams draining into the Kensico Reservoir provide less than two percent of the reservoir's water (virtually all of the rest arrives via aqueducts from the city's West-of-Hudson Catskill and Delaware system reservoirs), almost 50 percent of the total fecal coliform levels found in Kensico have been attributed to tributary flow from the Kensico watershed. Indeed, according to DEP, eight of nine reported fecal coliform concentrations that exceeded the federal health standards in 1997-98 at Kensico effluent locations were preceded by "significant rain events." This evidence strongly suggests that runoff in the Kensico watershed is a significant potential source of future coliform problems for the Kensico Reservoir.
Improperly operating septic systems are one potential source of runoff-generated coliform bacteria. When a septic system is operating correctly, domestic sewage wastes enter an underground tank where bacterial decomposition begins. The effluent then flows out of the tank into an adjacent septic field where remaining pollutants are removed via natural filtration. Solids remain in the tank and must be pumped out periodically. However, if there are problems with the siting, installation, or maintenance of septic systems, local ground or surface water supplies can be jeopardized. When septic systems fail, human wastes, containing bacteria, viruses and other microorganisms, as well as other pollutants, can flow out of septic fields and into surrounding water supplies. The city has, in recent years, identified numerous failing septic systems throughout the New York City watershed. According to DEP, there are approximately 750 septic systems in the Kensico watershed. Most were installed in the last couple of decades and are therefore less likely to fail. As they age, however, they might threaten the reservoir. Ominously, over 200 of these septic systems are within 300 feet of the Kensico Reservoir or 100 feet of a reservoir tributary.
The problems of septic system failures are compounded where new development occurs on steeply sloping terrain. This is a particular concern in the Kensico watershed because of the watershed's naturally hilly topography and because most of the remaining parcels for development are located on historically undesirable steep slopes. Despite these facts, however, state and city regulators have recently loosened safeguards that had prohibited new construction on parcels whose natural slopes are greater than 15 percent. (These actions, undertaken without public notification or comprehensive environmental review, triggered a lawsuit by environmental groups led by the Riverkeeper in 1998. The challenge is now pending in State Supreme Court in Queens County.)
Significantly, but with only scant media attention, high coliform counts have already led to a filtration order involving the Rye Lake portion of the Kensico Reservoir. The Westchester Joint Water Works (WJWW) is the entity that withdraws water from the Rye Lake side of Kensico and supplies it (either directly or indirectly) to the communities of Harrison, Mamaroneck, Port Chester, Rye, and Rye Brook. In 1993, the state Health Department concluded that conditions for filtration avoidance for the WJWW's Rye Lake water supply were not being met due to high coliform levels, and WJWW signed a stipulation requiring it to design and construct a filtration plant for its Rye Lake Supply. The WJWW believes the coliform bacteria may be entering the Rye Lake portion of the reservoir from the Westchester County Airport and Interstate 684. These facilities are located close to Rye Lake in the most paved-over sub-basin of the Kensico watershed. WJWW has recently placed a curtain in the reservoir in an attempt to divert the runoff away from intake pipes, and is hoping to convince the state that it can meet the filtration avoidance requirements and avoid having to construct a filtration plant. But if development continues to intensify around Rye Lake, WJWW's filtration avoidance hopes -- already a long shot -- would appear to be most unlikely. (New York City's Kensico water withdrawal site is located on the other side of the reservoir, so the city has not been affected by the filtration order for WJWW. But the situation illustrates that threats to the purity of the New York City supply have now approached the Kensico Reservoir itself.)
Another threat associated with increasing development and stormwater runoff in Kensico is turbidity. Turbidity, a measure of cloudiness of water, is a key water quality parameter. In addition to aesthetic problems associated with water that is higher in turbidity, the suspended particles in more turbid water decrease the effectiveness of disinfection (by providing places for microorganisms to hide and elude chlorine treatment). To be sure, the turbidity of the water leaving Kensico Reservoir is generally controlled by the quality of the water that enters the reservoir from the Catskill and Delaware Systems. But DEP studies have shown that under storm conditions substantial loads of sediment can enter the reservoir from local streams. If the Kensico watershed continues to develop, those loads are likely to increase. During one storm monitored by DEP, Malcolm Brook (the highly developed sub-basin described above) was found to have peak turbidity measurements 30 times those measured in the minimally developed Whippoorwill sub-basin. Although the massive sediment loading did not cause a violation of the turbidity standard in the water leaving Kensico on this occasion (most likely due to the pollution-diverting "curtain" placed in the reservoir by the city, see below), it serves as another warning of the potential effects of development mistakes.
(iii) Phosphorus and other nutrients
An additional potential threat to Kensico is the draining of phosphorus and other nutrients into the reservoir. Such nutrients, from lawn fertilizers, pet waste, and failing septic systems or sewer lines, can lead to excessive algae growth in reservoir water. This is a serious problem that can result in objectionable changes in taste and odor, increased cloudiness, and potential health risks (including increased levels of carcinogenic disinfectant byproducts and the production of algal toxins). In recent years, the Kensico Reservoir has experienced five algae blooms, each lasting at least three weeks. Although these short-term problems were most likely due to poor quality water coming from the West Branch Reservoir, nutrient runoff should be better controlled in both watersheds. Indeed, average phosphorus levels in the Kensico Reservoir already exceed the phosphorus standard that was recommended for the reservoir by DEP scientists in 1993.
(iv) Pesticides and other organic chemicals
A fourth warning sign that activities in the Kensico watershed could pose problems for the future of the Kensico Reservoir is the recent detection of pesticides and other organic chemicals in Kensico watershed tributaries. Even more startling, recent DEP monitoring has found very low but detectable levels of the herbicide Dalapon in water leaving Kensico. Although the Dalapon levels were well below the state drinking water quality standard, this was apparently the first time this herbicide was detected in the New York City drinking water supply. Other city water sampling detected low concentrations of polyaromatic hydrocarbons (PAH's) in two Kensico sub-basins -- the heavily developed Malcolm Brook area and the sub-basin that includes Interstate 684 and Westchester County Airport.
Another long-standing Kensico watershed trouble-spot that raises the threat of organic chemicals is the New York State Department of Transportation former landfill on Route 120. Located only about 1,500 feet from the Kensico Reservoir, this dump is now being cleaned up. But a petroleum spill from a leaking underground fuel tank at the facility has not yet been remediated.
To be sure, city, state, and federal agencies stress that the herbicide and PAH levels they found do not present a threat to consumers of New York City drinking water or violate state or federal standards. But pesticides and organic chemicals are persistent in the environment. And the detection of these chemicals coincides with increased development and concomitant pesticide use (on corporate lawns, residences and golf courses) in the Kensico watershed. For those interested in the future of the city's unfiltered water supply, these findings are grounds for concern. They are further proof that the impacts of runoff from intensified development in the Kensico basin are already being observed.
E. GOVERNMENT ACTIONS
City DEP officials say they understand the importance of safeguarding the Kensico watershed. DEP staff have spoken and written about the essential role this reservoir plays in delivering high quality drinking water to New York City and Westchester County residents. And the department has initiated a number of important programs to protect the Kensico. We summarize the most important of these programs in part (i) of this section. Yet, as we note in part (ii), their existing approach leaves significant problems remaining and unaddressed, threatening Kensico water quality over the long-term. While these officials understand the problems in theory, they are not in practice facing up to what is necessary to prevent the insidious decline of this watershed.
In one successful initiative, city officials mounted a program to keep waterfowl feces from contaminating the Kensico Reservoir. In the early 1990s, geese and gulls were identified by DEP as a source of elevated fecal coliform bacteria levels (during fall migration and over-wintering periods) at the Kensico Reservoir. DEP implemented a bird deterrent program, which included the erection of physical barriers as well as waterfowl hazing (using noisemakers, motorboats and bird distress tapes). This program, which continues today, has helped bring about a significant decline in reservoir-wide roosting populations of geese, gulls and other waterfowl, and has reduced the fall and winter coliform exceedances in the Kensico Reservoir.
Second, city officials have sought to control pollution runoff from the heavily developed Malcolm Brook sub-basin of the Kensico Reservoir. Their objective has been to reduce the amount of suspended solids, fecal coliform bacteria, and other pathogens in Malcolm Brook from entering the portion of the Kensico Reservoir where water is drawn into the city's distribution system. In 1995, DEP erected an 850 foot-long fabric curtain in the reservoir, at the mouths of Malcolm Brook and Young Brook, to direct pollution runoff away from the Catskill Aqueduct effluent chamber (through which water flows on its way to New York City). Following storm damage, the fabric curtain was repaired in 1997-98 by DEP-contracted divers.
A third element of the city's Kensico program is a plan to install new facilities to capture stormwater that now flows directly into the Kensico Reservoir. These controls, called BMPs, or best management practices, are intended to collect rainwater runoff and snow-melt to prevent fecal coliform bacteria and turbidity from entering the reservoir. After more than five years of planning, the city's BMP program for Kensico now envisions the construction of 44 detention basins and similar storm management facilities at various Kensico sub-basins, including Malcolm Brook. Construction of these BMPs has not yet begun.
Finally, the city has included the Kensico watershed in its program for acquisition of critical watershed lands. Indeed, the entire Kensico basin was designated by the city in 1996 as priority 1A and 1B lands -- the city's top two categories for acquiring lands through purchase or conservation easements.
Despite the city's Kensico activities to date, more will be needed -- much more in fact -- if the long term purity of the unfiltered Kensico Reservoir is to be assured for future generations of New Yorkers. This is true even for the programs that have already begun.
A prime example is the lack of progress in purchasing land or conservation easements in the Kensico watershed. New York City set aside funds for land purchases in critical watershed areas in 1993 and received a state permit to advance its program in the spring of 1997. As of November 1998, however, the city had not purchased a single acre of Kensico watershed land! To be sure, the city was negotiating to purchase several hundred Kensico acres last summer. But the pace of acquisition has been agonizingly slow. One gets the sense that, despite the progress of the land program in other parts of the city's watershed, city officials have more or less written off land purchases or easements in Kensico -- either because of the cost of land per acre in the watershed or because considerable development has already occurred. Most independent watershed experts, however, would strongly disagree with such a throw-in-the-towel approach for the city's most crucial reservoir.
Similar gaps, if not quite so glaring, appear in other aspects of the city's Kensico protection efforts. For example, the city's latest plan to construct 44 detention basins or other BMPs comes five years after the U.S. EPA first required a plan to reduce stormwater runoff into Kensico, as a condition for filtration avoidance. Nevertheless, proposed construction dates have come and gone and still none of these controls had been put in place as of December 1998. More fundamentally, even once installed, such BMPs are no panacea, according to watershed experts. BMPs, these experts note, lessen but do not remove the impacts of development. According to Tom Schueler, Executive Director of the Center for Watershed Protection: "BMPs can never compensate for poor watershed master planning, an inadequate stream buffer network, or sloppy site planning." Significantly, the city has apparently not considered the extent to which a BMP strategy might counter-productively open the way for even more development throughout the Kensico watershed.
On another issue of concern -- safeguarding the Kensico from pesticide runoff -- there is little apparent progress. Here it is the state that seems primarily responsible. In the early 1990s, DEP sought authority from New York State to review proposed commercial applications of pesticides in close proximity to reservoirs and their tributaries and to track the chemicals and quantities applied. However, even these modest proposals did not receive state support. Since then, efforts to address the concerns raised by DEP regarding pesticide applications in the watershed appear to have made little progress. This is troubling, especially in view of the recent report of detectable levels of one herbicide in water that was leaving the Kensico for the city's distribution system.
A fourth area of concern is the state's roadway expansion program in the Kensico watershed. This problem, discussed more fully above, is most glaringly exemplified by the proposed expansion of Route 22, immediately adjacent to the reservoir. Governor Pataki has not yet become personally involved in refocusing state road building projects to less sensitive locations.
Moreover, there is a fundamental flaw in the approach now being taken by the city and state to protect the Kensico watershed. With limited exceptions, the activities that New York officials are undertaking are designed to accommodate growth and to minimize the impacts of new pollution that the new growth generates. Rather than recognize the irreplaceable resources involved, and strive to protect and even restore this watershed, the existing programs accept as a given that continued development of this small watershed is inevitable and that the best that can be done is to mitigate the harm. Whatever wisdom that philosophy may have as a general approach to environmental problem-solving, it does not make sense when the resource in question is the terminal reservoir for the unfiltered drinking water supply of nine million New Yorkers.
1. The Hillview Reservoir, just north of the City line, is not a collecting reservoir -- that is, it does not receive runoff from surrounding lands.
2. These figures are based on 1990 census data. NYCDEP, "Kensico Reservoir Water Quality Control Program Final Environmental Impact Statement," December 1995, p. 5-1.
3. This category includes potentially developable properties such as land belonging to private clubs, public and private institutions, and public non-park land.
4. Information on development projects was obtained primarily from two sources: (1) NYCDEP "Quarterly Reports Describing Activities in the Watershed," submitted to EPA under the Filtration Avoidance Determination; and (2) visits to local planning boards to review development proposals and site plans.
5. "How Much is Enough Aid From Taxpayers to IBM?" Gannett Suburban Newspapers, June 10, 1998.
6. IBM owns another large parcel of land in the Kensico watershed. It is adjacent to the site described above, but is located in the town of Greenwich, Connecticut. Under current zoning, 266,000 sq. ft. of office space could be built on this site, although there are no plans to develop it at this time. NYSDOT, "Supplemental DEIS Routes 120 and 22, Section 7 and 8 Draft," November 6, 1998, pp.10-11.
7. Amended Site Plan Application - Swiss Re America (November 21, 1996), and Amended Site Plan Approval (February 24, 1997).
8. In a letter to the County Board of Legislators on November 24, 1998, GE announced that it was, at least temporarily, withdrawing its Westchester County Airport hanger extension plans. However, the final outcome of the proposed project is not known.
9. NYCDEP, "Notice of Modification to the Kensico Reservoir Water Quality Control Program," April 27, 1998, p. 2.
10. NYCDEP, "Kensico Reservoir Water Quality Control Program Draft Environmental Impact Statement," August 1995 p. 4-18.
11. Ibid., p. 4-19.
12. NYSDOT, "Supplemental DEIS Routes 120 and 22, Section 7 and 8 Draft," p. 23.
13. See, e.g., Tom Schueler, "Mitigating the Adverse Impacts of Urbanization on Streams: A Comprehensive Strategy for Local Government," EPA Seminar Publication, Nonpoint Source Watershed Workshop, September 1, 1991, p. 116: "The degree of pollutant loading has been shown to be a direct function of the percentage of watershed imperviousness."
14. NYCDEP, "Final Design Criteria Report," Appendix C, Table 4.1 Kensico Watershed SWMM Model Results, and Tom Schueler, "Developing Effective BMP Systems for Urban Watersheds," Watershed Restoration Source Book, April 1992, pp. 41-42.
15. NYCDEP, "Kensico Water Quality Program FEIS," December 1995, Table 2.3-1.
16. NYCDEP, "Kensico Watershed Study," July 1996, pp. 34, 78 and 91.
17. NYCDEP, "Kensico Watershed Study," July 1997, p. 71.
18. Chester L. Arnold, Jr. and C. James Gibbons, "Impervious Surface Coverage," Journal of the American Planning Association, Spring 96, p. 246, adapted from Schueler, "Developing Effective BMP Systems for Urban Watersheds," in Watershed Restoration Source Book, p. 40.
19. This is so because under the federal Safe Drinking Water Act and its implementing regulations, if there is a violation of water quality standards the city would no longer be entitled under law to avoid filtration of its water supply. 40 C.F.R. 141.71(a).
20. NYCDEP, "Kensico Watershed Study 1991-1993," Executive Summary; NYCDEP, "Kensico Watershed Study," July 1997, p. 30.
21. NYCDEP, "Kensico Watershed Study," July 1998, p. 15.
22. Ron Ohrel, "Dealing with Septic System Impacts," Watershed Protection Techniques, Fall 1995, p. 265.
23. NYCDEP, "Kensico Infrared Pilot Study," June 1995, p. 1. The remaining homes and businesses located in the Kensico watershed are hooked up to sewer systems that discharge wastewater outside of the watershed.
24. NYSDEC has found that the average life span of a septic system is 15-25 years.
25. NYCDEP, "FGEIS for the Proposed Watershed Regulations Vol. II," November 1993, Table VIII F-2.
26. 26. In the matter of filtration avoidance for the Westchester Joint Water Works, stipulation between Westchester Joint Water Works and New York State Department of Health (September 21, 1993).
27. 27. Tom Anderson, "Pollutants at airport pose danger to reservoir," The Journal News, January 17, 1999.
28. NYCDEP, "Kensico Watershed Study," July 1997, p. 64.
29. An example of development related turbidity occurred at the Swiss Re construction site. In February 1998, after discovering turbid runoff entering Kensico, inspectors traced the source to the Swiss Re site where some failed erosion practices were found. DEP issued a notice of violation and the problem was corrected.
30. NYCDEP, "Kensico Watershed Study," July 1996, p. 92.
31. G. Dennis Cooke et al., Restoration and Management of Lakes and Reservoirs (Lewis Publishers, 1993), p. 34.
32. NYCDEP, "DEIS, Treatment of the NYC Delaware, Catskill and Croton Reservoir Systems for the Control of Bacteria, Turbidity, Algae and Zebra Mussels," September 1997, p. 18.
33. NYCDEP, "Implications of Phosphorus Loading for Water Quality in NYC Reservoirs," December 1993, p. 57.
34. NYCDEP, "New York City Drinking Water Supply and Quality Statement," 1997.
35. NYCDEP, "Filtration Avoidance Annual Report," March 31, 1998, pp. 21-22.
36. NYCDEP, "Kensico Water Quality Program FEIS" p. 11-10; and personal communication with Mauricio Roma, NYSDOT, December 11, 1998.
37. NYCDEP, "Kensico Watershed Study," July 1998, pp. 23-25.
38. NYCDEP, "Kensico Water Quality Program DEIS," pp. 1-2.
39. NYCDEP, "Kensico Watershed Study," July 1998, p. 29.
40. Sub-basins were selected to receive BMPs based on six criteria including proximity of the sub-basin to the intake chambers of New York City's water distribution system, which are located on the far west side of the Kensico Reservoir. Intakes located in the Rye Lake portion of the reservoir, which serve communities in southeastern Westchester, were not considered.
41. NYCDEP, "Land Acquisition And Stewardship Program; Status Report," October 23, 1998, p. 2.
42. EPA urged NYC to purchase land in the Kensico basin in its comments on the Kensico BMP plan. EPA wrote, "NYCDEP should make every effort to stem future pollution sources and protect remaining open space areas by utilizing the Land Acquisition program in Kensico."
43. Tom Scheuler, "Mitigating the Adverse Impacts of Urbanization on Streams," in Watershed Restoration SourceBook, p. 29.
Get Updates and Alerts
Water on Switchboard
NRDC experts write about water efficiency, green infrastructure and climate on the NRDC blog.
Recent Water Posts
- New Report Shows That Healthy Soils Can Help in the Fight Against Climate Change
- posted by Ben Chou, 11/19/15
- Making Sense of the Clean Water Rule is Easy
- posted by Jon Devine, 11/17/15
- Not In Our National Interest
- posted by Rhea Suh, 11/6/15
NRDC Gets Top Ratings from the Charity Watchdogs
- Charity Navigator awards NRDC its 4-star top rating.
- Worth magazine named NRDC one of America's 100 best charities.
- NRDC meets the highest standards of the Wise Giving Alliance of the Better Business Bureau.