5 Old Jericho Turnpike Jericho, NY 11573 t. 516.433.7970 f. 516.433.7971 nassau@cornell.edu cce.cornell.edu/nassau
Long Island Untreated Sewage Discharge Impacts: Questions and Solutions Introduction – The United Stated Environmental Protection Agency (US EPA) defines combined sewer overflows (CSOs) as sewers designed to collect rainwater runoff, domestic sewage, and industrial wastewater in the same pipe, which when operating correctly, transport wastewater to treatment facilities which, ideally, treat and discharge the affected water properly. During heavy rainfall, wastewater may exceed sewer system or treatment plant capacities. Untreated sewage during overflow periods can contaminate water and soil, causing serious water quality problems. Sanitary sewage overflows can also back-up into basements, causing property damage and threatening public health.1 Due to the flooding and storm surge resulting from Hurricane Sandy, the Bay Park Sewage Treatment Plant discharged 104 million gallons of untreated sewage and an estimated 2.2 billion gallons of partially treated sewage into the surrounding area.2 Frequent questions arose in Sandy’s wake, once Long Islanders returned to their homes and businesses to assess their landscapes and subsequent storm impacts. Minimal research has been conducted on sanitary sewage overflow impacts on lawns and landscapes. A substantial portion of reported hurricane damage was attributable to extended wind and salt exposure. Sewage Sludge Research – Municipal sewage sludge (biosolids) is a by-product of sewage treatment containing home, industrial, business, stormwater, and landfill leachate (in some locations), as well as contaminants leached from pipes.3 The research that exists regarding sewage sludge is based upon its application to agricultural lands. Regulations adopted by the U.S. EPA regulations in 1993 establish minimum safety standards (metals and pathogens) if sewage sludge material is applied to agricultural land.4 Because sewage sludges are collected from municipal sources, contaminants and concentrations differ from those found in residential septic systems. Risks posed by sewage sludges result from the potential to contain a wide array of human pathogens, biological agents and industrial waste. Testing the entire possible contaminant spectrum is not economically feasible. Like many biological and environmental risks, risks posed by sewage sludges are correlated with exposure variables – including dosage and duration. A correlation exists between exposure levels (human and environmental) and the quantity of material applied to land. New York State regulations prohibit the use of sludge products made in New York State on crops for human consumption, such as in the home vegetable garden.5 Sandy-Related Sewage Contamination: Correlations and Comparisons – Most research addressing pollutant dilution is derived from limnological or hydrological data involving lakes and streams. Scant research exists, if any, regarding bacteria and contaminant migration through soil over time. However, from our growing understanding of post-Sandy events, along with agricultural biosolids application research, some correlations and recommendations can be made currently:
Generally, bacteria do not bind to soil particles effectively, and may be diluted through precipitation and rainfall events as a result (see data table below).6
Cool, moist conditions can prolong Streptococcus faecalis survival in soil for at least 12 weeks, however freezing temperatures are typically lethal, with population reduction at rates up to 95% when several freeze-thaw cycles occur.7
Normal operations were not resumed at the Bay Park facility for six weeks following Hurricane Sandy. Building Strong and Vibrant New York Communities Cornell Cooperative Extension in Nassau County provides equal program and employment opportunities.
Sufficient precipitation fell in the months following the Bay Park discharge to promote substantial contaminant migration through the soil column.8 Additionally, sufficient minimum temperatures in the December through March period reduced active bacterial populations significantly.
Spring 2013 soil sampling analysis conducted by Cornell Cooperative Extension of Nassau County Horticultural Expert, Vinnie Drzewucki, has indicated no evidence to date of elevated soil salinity in seawater-submerged South Shore locations.
Heavy metal soil contamination is a common sewage overflow and biosolid application impact.9
Crops cultivated in contaminated soil may uptake metals and be consumed by humans and livestock.10
If you intend to: grow edible crops; have children who have frequent contact with your lawn; or have pets that may ingest grass, it is recommended strongly to test soil for heavy metal contamination.
Low-cost soil testing is available through CCE (Cornell University) to ensure safe crop production.11
Further information about flooding related issues: NYS Emergency Disaster Education Network12 Post-Sandy Precipitation and Temperature Variations – December 2012 to June 2013 (Islip, NY) Temp (°F)
Precipitation
Month
Min
Mean
(inches)
December
31
41
6.1
January
14
33
2.3
February
23
32
5.9
March
31
39
2.6
April
37
50
1.5
May
48
59
3.1
June
62
67
4.9
Endnotes: 1
http://www.epa.gov/compliance/monitoring/programs/cwa/csos.html http://www.climatecentral.org/pdfs/Sewage.pdf 3 Harrison, E.Z., M.B. McBride and D.R. Bouldin. 1999. Land application of sewage sludges: an appraisal of the US regulations. Int. J. Environment and Pollution, 11(1):1-37. 4 40 CFR, Part 503. See http://cwmi.css.cornell.edu/Sludge/briefsummary.htm 5 NYS DEC Part 360 Rule. See http://www.gardening.cornell.edu/factsheets/orgmatter/index.html#biosolids; see also Harrison, E.Z., et al. 6 Celico, F., Varcamonti, M., Guida, M. and Naclerio, G. 2004. Influence of Precipitation and Soil on Transport of Fecal Enterococci in Fractured Limestone Aquifers. Appl. Environ. Microbiol. 70(5): 2843-47. 7 Kibbey, H. J., C. Hagedorn, and E. L. McCoy. 1978. Use of fecal enterococci as indicators of pollution in soil. Appl. Environ. Microbiol. 35:711-17. 8 National Weather Service Historical Data, McArthur Airport, Islip, NY (ISP). 9 Kapungwe, E.M. 2013. Heavy Metal Contaminated Water, Soils and Crops in Peri Urban Wastewater Irrigation Farming in Mufulira and Kafue Towns in Zambia. Journal of Geography and Geology; 5(2): 2013 10 Sloan, J.J., R. H. Dowdy, M. S. Dolan and D. R. Linden. 1997. Long-Term Effects of Biosolids Applications on Heavy Metal Bioavailability in Agricultural Soils. Journal of Environmental Quality. 26(4): 966-74. 11 Cornell University Soil Testing Lab, available at http://www.dairyone.com/AgroOne/soiltesting/default.htm. 12 http://eden.cce.cornell.edu/disasters/Pages/Floods.aspx 2
Building Strong and Vibrant New York Communities Cornell Cooperative Extension in Nassau County provides equal program and employment opportunities.
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