Appendix D
Analysis of Wastewater Treatment Plants and On-site Sewage Treatment and Disposal Systems: The Impact Index
This appendix describes the methods used creating the Impact Index found in Chapter 11. The Impact Index shows the relative pollutant loadings of wastewater treatment plants (WWTPs) and on-site sewage treatment and disposal systems (OSTDS) in individual reservoir basins. For each West-of-Hudson reservoir, Kensico Reservoir, and West Branch Reservoir, a worksheet similar to the one presented below was created. An explanation of each worksheet entry is given below, followed by the eight worksheets completed for each reservoir.
Impact Index Worksheet
Known Permanent Watershed Population1
Permitted Number of Sewage Treatment Plants2
Permitted Wastewater flow from WWTPs3
Discharger
Daily Flow
Known Number of OSTDS7
Estimated Wastewater flow from OSTDS8
Estimated Percent of Population served by OSTDS9
Estimated Population served by OSTDS (@2.5 persons/home)10
Parameter |
Input from OSTDS Now |
Input w/ upgrades |
Input 2010 w/ growth |
Phosphorus (lbs/day) |
|||
Giardia Cysts (106/day) |
|||
Fecal Coliforms (106/day) |
|||
Viruses (106/day) |
|||
Total Suspended Solids (lbs/day) |
|||
Cryptosporidium Oocysts (106/day) |
Notes
1. |
Population from NYC DEP (1993), and based on 1990 Census values. |
2. |
Permitted number of WWTPs from Table 5-4. |
3. |
Permitted flow from WWTPs from Table 5-4. |
4. |
Obtained from NYC DEP (1993 EIS), Table NC-2 "Existing, Expanded and New WWTPs Summary of No Action/Action Impact on Pollutant Loadings by District and Drainage Basin Totals." |
5. |
Obtained from NYC DEP (1993 EIS), Table NC-2 "Existing, Expanded and New WWTPs Summary of No Action/Action Impact on Pollutant Loadings by District and Drainage Basin Totals." |
6. |
Calculated by applying the growth rate observed for the period 1990 to 1996 to the period from 1990 to 2010. The observed annual growth rate of 0.25 percent for the West-of-Hudson basin resulted in a total population increase of 5 percent in 2010. The observed annual growth rate of 1.06 percent for the East-of-Hudson basin resulted in a total population increase of 21.2 percent for the Kensico and West Branch basins in 2010. |
7. |
Septic system numbers from NYC DEP (1993, Table VIII F-3). |
8. |
Based on 50 gallons of wastewater per day per person (Chanlett, 1979). |
9. |
Derived by dividing the estimated population served by OSTDS (#10) by the known permanent watershed population (#1). Values slightly exceeding 100 percent appears to reflect the fact that many of the WWTPs serve schools and not residential subdivisions, while values greatly exceeding 100 percent may be attributable to large numbers of seasonal residences. |
10. |
Calculated by multiplying the known number of OSTDS (#7) by 2.5 residents. This assumes that there is one OSTDS per residence, 2.5 occupants per residence, and that only residences (not commercial facilities) are served by OSTDS. 2.5 occupants per household is the figure for Florida derived from the 1990 Census values for population (12,937,926) divided by the number of households (5,138,360). |
11. |
This is the average value for total phosphorus (0.0082 lb/day) found in effluent from conventional septic tank and drainfield systems as reported by Ayres (1993). It has been multiplied by the estimated population served by OSTDS (#10). |
12. |
Assumes 6.4 percent of the population using OSTDS (#10) is positive for Giardia. This is based on the average of two CDC studies of prevalence of parasites in stool specimens which reported Giardia was found in 7.2 percent of samples examined in 1987 and 5.6 percent of samples examined in 1991 (Kappus et al., 1994). The number of positive residents is then multiplied by the maximum number of Giardia cysts excreted per day by an individual (9 × 106 cysts reported by Knight, 1980). This has been multiplied by 0.05 to reflect reported failure rates (defined as surfacing sewage) for conventional systems. This assumes that the remaining 95 percent of the systems are functional and remove all Giardia cysts. |
RESERVOIR: Kensico
Known Permanent Watershed Population |
4,432 |
Permitted Number of Wastewater Treatment Plants |
0 |
Permitted Wastewater flow from WWTPs (gallons/day) |
0 |
Known Number of OSTDS |
580 |
Estimated Wastewater flow from OSTDS (gallons/day) |
29,000 |
Estimated Percent of Population served by OSTDS |
31 |
Estimated Population served by OSTDS (@2.5 persons/home) |
1,450 |
Parameter |
Input from OSTDS Now |
Input w/ upgrades |
Input 2010 w/ growth |
Phosphorus (lbs/day) |
11.9 |
2.0 |
2.4 |
Giardia Cysts (106/day) |
42 |
0 |
0 |
Fecal Coliforms (106/day) |
146,770 |
0 |
0 |
Viruses (106/day) |
0.1 |
0 |
0 |
Total Suspended Solids (lbs/day) |
0 |
0 |
0 |
Cryptosporidium Oocysts (106/day) |
0.2 |
0 |
0 |
RESERVOIR: West Branch
Known Permanent Watershed Population |
3,210 |
Permitted Number of Wastewater Treatment Plants |
1 |
Permitted Wastewater flow from WWTPs (gallons/day) |
20,000 |
Discharger |
Daily Flow |
Clear Pool Camp |
20,000 |
Parameter |
Input from WWTPs Now |
Input w/ upgrades |
Input 2010 w/ growth |
Phosphorus (lbs/day) |
0.8 |
0.2 |
0.3 |
Giardia Cysts (106/day) |
13.6 |
13.6 |
16.3 |
Fecal Coliforms (106/day) |
302.8 |
302.8 |
363.4 |
Viruses (106/day) |
0.4 |
0.4 |
0.5 |
Total Suspended Solids (lbs/day) |
3.3 |
1.7 |
2.0 |
Cryptosporidium Oocysts (106/day) |
1.2 |
1.2 |
1.4 |
Known Number of OSTDS |
1,777 |
Estimated Wastewater flow from OSTDS (gallons/day) |
222,125 |
Estimated Percent of Population served by OSTDS |
138 |
Estimated Population served by OSTDS (@2.5 persons/home) |
4,443 |
Parameter |
Input from OSTDS Now |
Input w/ upgrades |
Input 2010 w/ growth |
Phosphorus (lbs/day) |
36.5 |
6.1 |
7.3 |
Giardia Cysts (106/day) |
128 |
0 |
0 |
Fecal Coliforms (106/day) |
1,139,501 |
0 |
0 |
Viruses (106/day) |
0.9 |
0 |
0 |
Total Suspended Solids (lbs/day) |
0 |
0 |
0 |
Cryptosporidium Oocysts (106/day) |
0.5 |
0 |
0 |
RESERVOIR: Ashokan
Known Permanent Watershed Population |
14,294 |
Permitted Number of Wastewater Treatment Plants |
6 |
Permitted Wastewater flow from WWTPs (gallons/day) |
605,826 |
Discharger |
Daily Flow |
Belleayre Mt. Ski Center |
29,000 |
Camp Timberlake |
34,000 |
Onteora Schools |
27,000 |
Mountainside Rest |
3,076 |
Pine Hill WWTP |
500,000 |
Rotron, Inc. |
12,750 |
Parameter |
Input from WWTPs Now |
Input w/ upgrades |
Input 2010 w/ growth |
Phosphorus (lbs/day) |
2.0 |
1.3 |
1.4 |
Giardia Cysts (106/day) |
113.4 |
113.4 |
120.2 |
Fecal Coliforms (106/day) |
1070.3 |
1070.3 |
1134.5 |
Viruses (106/day) |
3.5 |
3.5 |
3.7 |
Total Suspended Solids (lbs/day) |
5.3 |
5.3 |
5.6 |
Cryptosporidium Oocysts (106/day) |
11.2 |
11.2 |
11.9 |
Known Number of OSTDS |
5,360 |
Estimated Wastewater flow from OSTDS (gallons/day) |
670,000 |
Estimated Percent of Population served by OSTDS |
94 |
Estimated Population served by OSTDS (@2.5 persons/home) |
13,400 |
Parameter |
Input from OSTDS Now |
Input w/ upgrades |
Input 2010 w/ growth |
Phosphorus (lbs/day) |
110.0 |
18.3 |
19.4 |
Giardia Cysts (106/day) |
386 |
0 |
0 |
Fecal Coliforms (106/day) |
3,437,100 |
0 |
0 |
Viruses (106/day) |
2.8 |
0 |
0 |
Total Suspended Solids (lbs/day) |
0 |
0 |
0 |
Cryptosporidium Oocysts (106/day) |
1.4 |
0 |
0 |
RESERVOIR: Schoharie
Known Permanent Watershed Population |
17,662 |
Permitted Number of Wastewater Treatment Plants |
19 |
Permitted Wastewater flow from WWTPs (gallons/day) |
1,751,113 |
Discharger |
Daily Flow |
Camp Loyaltown, Inc. |
21,000 |
Colonel Chair Estates |
30,000 |
Crystal Pond Townhouse |
36,000 |
Elka Park |
10,000 |
Forester Motor Lodge |
3,900 |
Frog House Restaurant |
1,788 |
Golden Acre Farms |
9,200 |
Grand George WWTP |
500,000 |
Harriman Lodge |
20,000 |
Hunter Highlands |
80,000 |
Latvian Church Camp |
7,000 |
Liftside at Hunter Mountain |
81,000 |
Mountain View Estates |
13,000 |
Ron-De-Voo Restaurant |
1,000 |
Snowtime |
120,000 |
Tannersville WWTP |
800,000 |
Thompson House Inc. |
4,775 |
Whistle Tree Development |
12,450 |
Parameter |
Input from WWTPs Now |
Input w/ upgrades |
Input 2010 w/ growth |
Phosphorus (lbs/day) |
12.7 |
4.5 |
4.8 |
Giardia Cysts (106/day) |
536.9 |
299.3 |
317.3 |
Fecal Coliforms (106/day) |
3,718.4 |
2,567.8 |
2,721.9 |
Viruses (106/day) |
16.5 |
9.3 |
9.9 |
Total Suspended Solids (lbs/day) |
29.7 |
10.7 |
11.3 |
Cryptosporidium Oocysts (106/day) |
53.0 |
30.8 |
32.6 |
Known Number of OSTDS |
7,869 |
Estimated Wastewater flow from OSTDS (gallons/day) |
98,363 |
Estimated Percent of Population served by OSTDS |
111 |
Estimated Population served by OSTDS (@2.5 persons/home) |
19,673 |
Parameter |
Input from OSTDS Now |
Input w/ upgrades |
Input 2010 w/ growth |
Phosphorus (lbs/day) |
161.7 |
26.9 |
28.5 |
Giardia Cysts (106/day) |
567 |
0 |
0 |
Fecal Coliforms (106/day) |
504,602 |
0 |
0 |
Viruses (106/day) |
0.4 |
0 |
0 |
Total Suspended Solids (lbs/day) |
0 |
0 |
0 |
Cryptosporidium Oocysts (106/day) |
2.1 |
0 |
0 |
RESERVOIR: Cannonsville
Known Permanent Watershed Population |
17,000 |
Permitted Number of Wastewater Treatment Plants |
7 |
Permitted Wastewater flow from WWTPs (gallons/day) |
2,000,000 |
Discharger |
Daily Flow |
Delaware-BOCES |
2,500 |
Delhi |
515,000 |
SEVA Institute |
7,800 |
Allen Center |
20,000 |
Stamford WTP |
500,000 |
Village of Hobart |
160,000 |
Walton WTP |
1,170,000 |
Parameter |
Input from WWTPs Now |
Input w/ upgrades |
Input 2010 w/ growth |
Phosphorus (lbs/day) |
86.6 |
4.3 |
4.6 |
Giardia Cysts (106/day) |
69,658.6 |
22,847.3 |
24,217.8 |
Fecal Coliforms (106/day) |
1,471.9 |
1,324.0 |
1,403.4 |
Viruses (106/day) |
253.3 |
82.2 |
87.1 |
Total Suspended Solids (lbs/day) |
287.3 |
6.3 |
6.7 |
Cryptosporidium Oocysts (106/day) |
6,473.3 |
308.5 |
327 |
Known Number of OSTDS |
8,388 |
Estimated Wastewater flow from OSTDS (gallons/day) |
1,048,500 |
Estimated Percent of Population served by OSTDS |
123 |
Estimated Population served by OSTDS (@2.5 persons/home) |
20,970 |
Parameter |
Input from OSTDS Now |
Input w/ upgrades |
Input 2010 w/ growth |
Phosphorus (lbs/day) |
172.3 |
28.70 |
30.4 |
Giardia Cysts (106/day) |
604 |
0 |
0 |
Fecal Coliforms (106/day) |
5,378,805 |
0 |
0 |
Viruses (106/day) |
4.4 |
0 |
0 |
Total Suspended Solids (lbs/day) |
0 |
0 |
0 |
Cryptosporidium Oocysts (106/day) |
2.2 |
0 |
0 |
RESERVOIR: Pepacton
Known Permanent Watershed Population |
15,622 |
Permitted Number of Wastewater Treatment Plants |
6 |
Permitted Wastewater flow from WWTPs (gallons/day) |
579,400 |
Discharger |
Daily Flow |
Camp NuBar |
12,500 |
Camp Tai Chi |
7,500 |
Margaretville WWTP |
400,000 |
Mountainside Farms, Inc. |
49,800 |
Regis Hotel |
9,600 |
Roxbury Run Village |
100,000 |
Parameter |
Input from WWTPs Now |
Input w/ upgrades |
Input 2010 w/ growth |
Phosphorus (lbs/day) |
8.6 |
1.5 |
1.6 |
Giardia Cysts (106/day) |
227.2 |
82.1 |
87 |
Fecal Coliforms (106/day) |
2,396.3 |
407.2 |
431.6 |
Viruses (106/day) |
7.0 |
2.6 |
2.8 |
Total Suspended Solids (lbs/day) |
21.9 |
3.3 |
3.5 |
Cryptosporidium Oocysts (106/day) |
23.5 |
8.9 |
9.4 |
Known Number of OSTDS |
6,417 |
Estimated Wastewater flow from OSTDS (gallons/day) |
802,150 |
Estimated Percent of Population served by OSTDS |
103 |
Estimated Population served by OSTDS (@2.5 persons/home) |
16,043 |
Parameter |
Input from OSTDS Now |
Input w/ upgrades |
Input 2010 w/ growth |
Phosphorus (lbs/day) |
131.9 |
22.0 |
23.3 |
Giardia Cysts (106/day) |
462 |
0 |
0 |
Fecal Coliforms (106/day) |
4,115,029 |
0 |
0 |
Viruses (106/day) |
3.4 |
0 |
0 |
Total Suspended Solids (lbs/day) |
0 |
0 |
0 |
Cryptosporidium Oocysts (106/day) |
1.7 |
0 |
0 |
RESERVOIR: Rondout
Known Permanent Watershed Population |
4,170 |
Permitted Number of Wastewater Treatment Plants |
1 |
Permitted Wastewater flow from WWTPs (gallons/day) |
180,000 |
Discharger |
Daily Flow |
Grahamsville WWTP |
180,000 |
Parameter |
Input from WWTPs Now |
Input w/ upgrades |
Input 2010 w/ growth |
Phosphorus (lbs/day) |
0.3 |
0.3 |
0.3 |
Giardia Cysts (106/day) |
12.7 |
12.7 |
13.5 |
Fecal Coliforms (106/day) |
33.5 |
33.5 |
35.5 |
Viruses (106/day) |
0.4 |
0.4 |
0.4 |
Total Suspended Solids (lbs/day) |
0.1 |
0.1 |
0.1 |
Cryptosporidium Oocysts (106/day) |
1.5 |
1.5 |
1.6 |
Known Number of OSTDS |
1,414 |
Estimated Wastewater flow from OSTDS (gallons/day) |
176,750 |
Estimated Percent of Population served by OSTDS |
85 |
Estimated Population served by OSTDS (@2.5 persons/home) |
3,535 |
Parameter |
Input from OSTDS Now |
Input w/ upgrades |
Input 2010 w/ growth |
Phosphorus (lbs/day) |
29.1 |
4.8 |
5.1 |
Giardia Cysts (106/day) |
102 |
0 |
0 |
Fecal Coliforms (106/day) |
906,728 |
0 |
0 |
Viruses (106/day) |
0.7 |
0 |
0 |
Total Suspended Solids (lbs/day) |
0 |
0 |
0 |
Cryptosporidium Oocysts (106/day) |
0.4 |
0 |
0 |
RESERVOIR: Neversink
Known Permanent Watershed Population |
1,557 |
Permitted Number of Wastewater Treatment Plants |
0 |
Permitted Wastewater flow from WWTPs (gallons/day) |
0 |
Known Number of OSTDS |
822 |
Estimated Wastewater flow from OSTDS (gallons/day) |
102,750 |
Estimated Percent of Population served by OSTDS |
132 |
Estimated Population served by OSTDS (@2.5 persons/home) |
2,055 |
Parameter |
Input from WWTPs Now |
Input w/ upgrades |
Input 2010 w/ growth |
Phosphorus (lbs/day) |
16.9 |
2.8 |
3.0 |
Giardia Cysts (106/day) |
59 |
0 |
0 |
Fecal Coliforms (106/day) |
527,108 |
0 |
0 |
Viruses (106/day) |
0.4 |
0 |
0 |
Total Suspended Solids (lbs/day) |
0 |
0 |
0 |
Cryptosporidium Oocysts (106/day) |
0.2 |
0 |
0 |
REFERENCES
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Ayres, A. 1993. Onsite Sewage Disposal Systems Research in Florida: An Evaluation of Current OSDS Practices in Florida . Tallahassee: Florida Department of Health and Rehabilitative Services.
Canter, L. W., and R. C. Knox. 1986. Septic Tank System Effects on Groundwater Quality. Chelsea, MI: Lewis Publishers Inc.
Chanlett, E. T. 1979. Environmental Protection. New York, NY: McGraw-Hill.
Goodgame, R. W., R. M. Genta, A. C. White, and C. L. Chappell. 1993. Intensity of infection in AIDS-associated cryptosporidiosis. Journal of Infectious Diseases 167:704–709.
Kappus, K. D., R. G. Lundgren, Jr., D. D. Juranek, J. M. Roberts, and H. C. Spencer. 1994. Intestinal parasitism in the United States: Update on a continuing problem. Am. J. Trop. Med. Hyg. 506:705–713.
Knight, R. 1980. Epidemiology and transmission of giardiasis. Transactions of the Royal Society of Tropical Medicine and Hygiene 74(4):433–435.
Marx, R., and E. Goldstein. 1993. A guide to New York City's reservoirs and their watersheds. New York, NY: Natural Resource Defense Council.
New York City Department of Environmental Protection (NYC DEP). 1993. Final Generic Environmental Impact Statement for the Proposed Watershed Regulations for the Protection from Contamination, Degradation, and Pollution of the New York City Water Supply and its Sources . November 1993. Corona, NY: NYC DEP.