By Sara Jerome,

@sarmje

Phosphorus and nitrogen levels in most New Jersey waterways have either dropped or held steady since the 1970s, according to a new federal study.

“What it shows us is our strategies in enhancing water quality have been working,” said Larry Hajna, a spokesman for the New Jersey Department of Environmental Protection (DEP), per New Jersey 101.5.

The study from the U.S. Geological Survey (USGS), a federal scientific agency, examined water-quality trends in New Jersey between 1971 and 2011. The DEP described how the study was conducted in a release:

The DEP commissioned the USGS to analyze data from 28 monitoring stations — including the Wallkill River, in Sussex County — for long-term trends in levels of nitrogen and phosphorus present in waterways. In all, the USGS analyzed more than 82,000 data points collected over a 41-year period from a variety of urban, suburban, agricultural and protected areas.

“Trend results for water years 1980 to 2011 in the combined set show that few of the 28 stations have upward trends in concentrations of either total nitrogen or total phosphorus,” the study said.

How did New Jersey achieve these results?

“Hajna said what we’ve seen is the development of wastewater treatment plants, from smaller, local facilities into more modernized, regionalized plants,” the news report said. Hajna added: “That has led to a reduction in the types of nutrients that can impair our waterways, specifically phosphorus and nitrogen.”

He noted that fertilizer formulation laws have had an impact on water quality in the state.

“Another contributor was a state program that requires local governments to implement stormwater control standards and best-management practices on issues such as animal waste ordinances, public education on stormwater, and other steps to reduce the impacts of stormwater runoff,” NJ Spotlight reported.

Tim Dillingham, executive director of the New Jersey-based American Littoral Society, weighed in on the study, per NJ Spotlight. He said the report shows progress but most state waterways do not meet "fishable and swimmable" standards.

“I don’t think you can make the argument that our work is finished,” Dillingham said, per the report. “The investment has paid off but that’s not to say that our waters are as clean as they should be.”

To read more about eliminating nitrogen and phosphorus in waterways visit Water Online’s Nutrient Removal Solutions Center.