The New York State Department of Conservation (DEC) recently announced it is taking the first step to create a clean water plan, which will improve water quality in the Wallkill Watershed.

The DEC initiated the Total Maximum Daily Load (TMDL) process for the watershed, the first step in a clean water plan. A TDML outlines the maximum amount of pollutant a waterbody can receive and still meet water quality standards.

From the TDML, the DEC learns what pollutants have the most impact. The DEC then identifies practices to address the sources in an implementation plan that becomes a part of the TDML. An implementation plan may include recommendations to improve agricultural practices, repair or replace septic systems, sewer a community of homes, or manage aquatic plants.

A plan may also include more restrictive construction requirements and stricter discharge limits for wastewater treatment plans (WWTP).

The Wallkill River has documented persistent water quality problems related to nutrient pollution. Multiple sections of the New Jersey section are classified as impaired by the New Jersey Department of Environmental Protection for pathogens, nutrients and arsenic. The New York side of the river is listed as draft impaired for nutrients by the DEC.

Jennifer Epstein, Water Quality Program Scientist for Riverkeeper, presented the findings of a Riverkeeper Community Monitoring study at the Wallkill River Summit on May 16. The study tested for enterococcus counts in the water, an indicator of fecal contamination.

The study found high levels of fecal contamination in the Wallkill. Samples collected from 2010 to 2018 found an average of 502 cells per 100 mL, the second highest of 13 waterbodies sampled. The Environmental Protection Agency threshold for safe swimming is 30 cells per 100 mL.

Riverkeeper tested for four categories of fecal contamination: human, wild bird, equine and bovine. While wild bird contamination had the highest fecal contamination, there was also a significant amount of human fecal contamination and, to a lesser extent, fecal contamination from cows.

“The human [fecal contamination] is our first concern because human-related contamination is the biggest known health concern and we’re interested in what we can do to fix water quality problems related to human infrastructure,” Epstein said.

The Wallkill has a much higher municipal effluent discharge from municipal water systems than its neighbors. Municipal water systems are aged and impact water quality. The Wallkill has 20 WWTP facilities discharging into the river, the highest of nine facilities sampled.

“The Wallkill has a huge load of effluent coming into it from municipal facilities,” Epstein said. “It’s way out of scale compared to its neighbors and it’s no secret that these facilities and the conveyance systems that bring wastewater to them are aging out. They are beyond their useful lives. They are not always maintained as they should be and there are water quality problems related to that.”

Epstein identified several problem areas, including the river section at the Orange and Ulster county lines between Walden and Wallkill, which is supposed to be suitable for swimming. The micropollutant concentrations were the highest of any in the Hudson River Estuary outside of WWTP outfalls. It was the most impacted by micropollutants specifically associated with wastewater.

The site is two miles downstream of the Walden WWTP, which is an old and problematic plant.

“The Walden wastewater treatment plant is a problem,” Epstein said. “It’s over capacity; its got a chronic and diverse series of effluent and reporting violations. The pipes are pretty old, over seventy years old.”

The Walden WWTP also has a wet weather bypass to the Tin Brook, which discharges untreated water during extremely wet weather.

“Within the operating permit of this waster water treatment plant, it is allowed to, during very high rain, discharge a combination of raw sewage and storm water into Tin Brook in order to not overwhelm the capacity of the plant,” Epstein said.

Brian Duffy, DEC division of water, stream and biomonitoring unit, also presented at the summit. DEC studies assessing nutrients in the Wallkill for 2017 and 2018 revealed a high level of nitrogen and phosphorus.

“It’s high,” Duffy said. “I don’t think that’s a surprise to anyone, but it’s documenting something that we already know and that’s an important step in the process towards addressing the issue.”

The DEC also tested for impacts to aquatic life, which is measured through a biological assessment profile (BAP) score. Seven sites on the Wallkill had a BAP score that produced impaired conditions for aquatic life.

The DEC also monitors harmful algal blooms, which have mostly not occurred since major blooms in the Wallkill in 2016.