Any conversation about sewage management in Suffolk County should begin with the current state of our waters. In conformance with the federal Clean Water Act, the New York State Department of Environmental Conservation assesses water bodies throughout the state. Numerous water bodies throughout Long Island are classified as “Impaired Waters” (303d list).
In plain talk, it means polluted. The next time you drive past a pond, creek or bay in your community, ask yourself if it’s on the list. Very likely it is.
These unfortunate designations are due to excessive levels of bacterial contamination and/or too much nitrogen. High levels of bacteria have caused the closure of thousands of acres of shellfish beds, while excessive nitrogen levels have triggered algal blooms that turn our bays to opaque colors of green, brown, red and every shade in between. It’s widely acknowledged that water pollution from sewage wastewater discharges have degraded the water we drink and our estuaries.
While there is general consensus that wastewater nitrogen needs to be reduced to restore water quality, the question is, how are we going to do it?
The Suffolk County Department of Health Services regulates nitrogen levels in groundwater for the sole purpose of protecting public health. Specifically, they manage the collective sewage wastewater discharges into groundwater to ensure safe drinking water. The nitrogen limit for drinking water is 10 milligrams per liter (mg/l). This level of nitrogen is 20 times higher than our coastal waters can sustain for biological health. Suffolk County’s Comprehensive Water Resources Management Plan reported increases in groundwater nitrogen levels in the Upper Glacial and Magothy aquifers of 200 percent and 38 percent, respectively. This causes great concern given our reliance on these water supplies and the connection to surface waters.
There are approximately 200 sewage treatment plants throughout Suffolk County. Although sewer treatment plants are being touted by some politicians as the answer to the region’s water quality problems, there are concerns that need to be addressed before we jump on the sewer plant bandwagon. Namely, their track record of poor performance, actual benefit to water quality and pretext for increased housing density.
I have periodically assessed the performance of Suffolk’s sewer treatment plants by reviewing monthly discharge monitoring reports. The reports disclose if the facility is effectively treating wastewater (i.e. removing nitrogen) and is in compliance with nitrogen discharge limits. They also reveal the performance of both the health department and the DEC in fulfilling their regulatory responsibility and diligent enforcement of the permits they issue.
My conclusion is that, although sewer treatment plants have the capability to significantly reduce wastewater nitrogen concentrations, improvements to local water quality are usually not realized. Many of the plants are under-performing, while regulatory enforcement is woefully lacking. Moreover, the plants are tied to dramatic increases in housing density, which increases nitrogen loadings to ground and surface waters. Extending sewer lines into outlying areas leads to sprawl development that diminishes environmental quality and places additional financial burdens on government services and school districts.
When the narrative of our elected leaders emphasizes economic growth over cleaning up our waters, their logic warrants scrutiny. Suffolk County’s ambitious plans for new sewer projects need to be carefully examined to ensure that achieving water quality improvements is the priority.
While small-scale private and municipal sewage treatment systems are viable tools in managing water quality, so too are alternative systems that have demonstrated high denitrifi cation performance. The best technologies available for sewage treatment systems can attain nitrogen reduction as low as 3 mg/l. While Suffolk County is beginning to approve their use, albeit at a snail’s pace, they have yet to require them as a condition for approving new sources of effluent. Instead, the health department’s bureaucratic indifference perpetuates the use of conventional septic systems, which collectively has caused the degradation of our waters.
The failed Water Quality Control Act sponsored by state Senator Ken LaValle and Assemblyman Robert Sweeney fell short in enacting meaningful sewage and agricultural reforms. With a do-over pending, there’s an opportunity to get it right by strengthening its weaknesses and including water protection measures necessary to achieve meaningful results. Going forward, we must defi ne the level of nitrogen removal necessary to protect our waters on a watershed-by-watershed basis, and enact water body-specific numeric nutrient standards. Numeric standards provide an import benchmark for water body health and identify where we need to be in regard to restoration.
New York State has developed numeric standards for certain water body types, but their findings have been kept under wraps because of political sensitivities. That is to say, objections from the agricultural and development interests who are content with the way things are. It’s time for our state elected officials to direct the DEC to publish the nutrient standards they prescribe so public debate can commence without further delay.
Kevin McAllister, a marine scientist, is a founder and president of Defend H20, a nonprofit water quality advocacy group. He lives in Quogue.