PROVIDENCE — A new draft report on the health of Rhode Island’s 890 fresh and saltwater bodies shows that while pollution persists, in most cases, it has not worsened during the past two years.

Rhode Island Department of Environmental Management (DEM) principal environmental scientist Heidi Travers explained the evaluations of water quality are based on whether the water meets standards for drinking, swimming, fish and shellfish consumption, and aquatic life.

“The goal is, you want to be able to safely consume fish, you want to be able to safely swim, and you want to create a safe habitat for aquatic life,” she said. “Every single waterbody has those three goals, so that’s what we’re assessing.”

The draft of impaired waters list, part of a statewide water quality assessment, was discussed Jan. 25 at a virtual workshop hosted by DEM. Issued every two years, the report is mandated by the Environmental Protection Agency (EPA) under the Clean Water Act. The 2020 assessment showed 22 percent of the state’s waterbodies were impaired by pollutants.

The draft assessment contains some encouraging news for sections of the Blackstone River and Buckeye Brook, as well as the Maidford, Pawtuxet and Woonasquatucket rivers.

While other pollutants are present, certain contaminants of particular concern have been reduced to the point where sections of the Blackstone and Buckeye rivers are no longer required to be included on the impaired waters list. In the Blackstone River, levels of dissolved lead no longer regularly exceed safe limits, possibly because of ongoing habitat restoration efforts.

“While there are no specific actions that can be directly linked to the removal of the dissolved lead impairment from the Blackstone River, many restoration activities have occurred in the watershed that likely contribute to the decline,” according to the draft assessment.

Waterbodies are assigned categories from 1-5, with Category 1 water data meeting the standards for the cleanest water. The EPA requires states to assign a single category to a waterbody. Waters designated as Category 2 meet the standards for all their designated uses. Category 3 waters have insufficient data for their usage goals. The data for Category 4 and 5 waters indicate impairment that prevents the waterbodies from meeting even one of the goals.

Category 1 waters meet all the goals and the data show they are not polluted. However, Travers noted Rhode Island has no Category 1 waterbodies — not because there are no clean waters, but because there is missing data.

Category 5 waters are sufficiently impaired that they require a water quality restoration study, which the EPA calls a Total Maximum Daily Load (TMDL). About 190 of Rhode Island’s waters, or about 20 percent, are listed as Category 5.

In Buckeye Brook, near T.F. Green International Airport in Warwick, the pollutant prompting the TMDL is dissolved zinc. But even after the reduction of zinc, the brook will remain impaired for aquatic life and swimming and other recreational uses. Jane Sawyers, of DEM’s Office of Water Resources, said the agency will continue to evaluate the brook as part of an ongoing river monitoring program.

“A field study was conducted that went out and collected data in Buckeye Brook and tributaries to Warwick Pond,” she said. “It was determined that in these cases, that it was a combination of metals; for Buckeye Book, cadmium, copper, iron and lead, and, previously, zinc.”

DEM is continuing to study the Melville Pond system, which includes two reservoirs on Aquidneck Island that are impaired by phosphorus.

“This is a nutrient that can cause an overabundance of nutrients and poor water quality conditions,” Sawyers said. “Melville Pond suffers from long-lasting algal and cyanobacteria [blue green algae] conditions as well.”

Another ongoing TMDL study is taking place in the tidal section of the Pawcatuck River and Little Narragansett Bay, where nutrient overloads and oxygen depletion have been persistent issues.

“This, again, is aquatic life use impairment, associated with nutrient enrichment and dissolved oxygen,” Sawyers said.

Overall, the health of Rhode Island’s waters has not changed significantly in the two years since the previous assessment was released.

“There’s a very small change, overall, between the combined [2018-2020] cycle,” Sawyers said. “The biggest movement was in the removal of impairments due to new data.”

The Clean Water Act requires the state to solicit public participation in the Category 5 assessment process.

“While we do accept comments on all of the waters, we really are soliciting comments on those Category 5 waters,” Travers said.

The public comment period will remain open until Feb. 18. Questions can be sent to Travers at [email protected].