APCC: Cape Cod ponds need a '208' study

ORLEANS – Citing a lack of data needed to measure and improve the health of the Cape’s freshwater ponds, Association to Preserve Cape Cod is calling on county government and the Cape Cod Commission to undertake a 208 water quality study for ponds on a scale that was done for the coastal bays.

Back in 2013 the state Department of Environmental Protection directed the commission to prepare an update to the 1978 Water Quality Management Plan for Cape Cod to address the degradation of the Cape’s water resources from excessive nutrients, primarily nitrogen from septic tanks.

The 208 Plan addressed bays and estuaries, and was the catalyst for several mitigation projects, such as the sewer infrastructures being installed in Chatham, Harwich and Orleans, and the four-town agreement to meet nitrogen reduction goals in Pleasant Bay, for example.

“The original 208 Plan identified ponds as needing detailed analysis, but it was deemed as outside the scope and budget, and was identified as a need for a future 208 study. APCC is saying now is the time for the study,” Andrew Gottlieb, executive director of the APCC, said Tuesday.

His comments came on the heels of the APCC’s 2020 State of the Waters: Cape Cod report, which studied salt and freshwater resources (capecodwaters.org). The Cape has 900-plus freshwater ponds, comprising some 11,000 acres. Many are bordered by residential development.

Ponds are considered are integral to the Cape's tourism economy -- for boating, fishing and swimming -- and are an important part of the region's wildlife ecosystem.

“Our objective is to use the State of the Waters: Cape Cod project as a graphic tool to illustrate the extent that the Cape’s water resources are impaired and to move the public and policy makers toward taking the necessary actions to clean up Cape Cod’s waters,” Gottlieb said in a statement that accompanied the report, issued in late October.

“Our findings this year also show that the real lack of data for freshwater ponds is holding up action to improve pond water quality. This hampers the effort to protect public health and delays efforts to restore ponds,” he said.

Ninety three ponds were graded in the report and 39 of them, or 42 percent, had unacceptable quality, up from 39 percent last year. They were graded by the Carlson Trophic Index, which uses a Secchi disk to measure visibility and total phosphorus and chlorophyll content.

Gottlieb said there is a lack of pond data. The APCC combined its cyanobacteria data with older water quality data to compile the report, but only 29 ponds, not including those monitored for toxic algae, have recent (since 2015) data.

“With freshwater ponds there are roughly 45 or so we’re evaluating using cyanobacteria occurrence, which the APCC or Barnstable are responsible for,” Gottlieb said.

Cyanobacteria can be harmful to people and animals.

In addition to leading to eutrophication of local ponds and embayments, excess nutrients fueled spring and summer algae blooms including toxic cyanobacteria. The number of ponds being temporarily closed is a new a phenomenon. Long Pond in Barnstable, Walkers and Cliff ponds in Brewster, and Mars and Deep ponds in Falmouth all had high levels last summer.

Wastewater from septic systems trickling through the groundwater into estuaries and ponds is the prime driver for degraded water quality. Septic systems, even Title Five systems, don’t remove much nitrogen or phosphorus from the water. Nitrogen fertilizes the ocean, phosphorus fertilizes fresh water systems. The construction of sewers will have the biggest impact on reducing pollution but that will take time.

Even if the source is stopped, phosphorus already in the groundwater or pond sediments will continue cycling through the system.

“Sewer construction offers some opportunity to improve quality of the water but there is a time lag with construction projects beginning and still under way,” Gottlieb said. “Chatham is an exception but Orleans is early and Harwich is a little further along. One of the challenges we face is even when we embark on a solution it takes several years before it’s up and running and everyone is hooked up. ”

Towns have also worked to reduce fertilizer runoff from golf courses and recreational land. Some have imposed residential restrictions but those are difficult to enforce.

“Eliminating fertilizer always helps,” Gottlieb said. “But it is unlikely fertilizer reduction alone would solve the problem. No matter what you’re going to want to stop as much additional input of nutrients as you can. There are steps a homeowner can take; all a green lawn gets you is a green pond. You don’t need a green lawn down to the water’s edge. A putting green lawn is not normal on Cape Cod.”