MARSTONS MILLS — On a quiet cranberry bog off Whistleberry Drive, an experiment is underway that eventually could have a profound effect on cleaning the Cape’s nitrogen-choked waterways.

In late July, a woodchip-based Bioreactor Nitrogen Reduction Pilot Project — the first of its kind in the world — was initiated at the head of the Marstons Mills River.

The project is being managed by the Barnstable Clean Water Coalition, which has partnered with the U.S. Environmental Protection Agency, the Nature Conservancy and Mount Holyoke College.

The bog acts as a collection system for nitrogen-contributing septic systems that surround the upper reaches of the Three Bays watershed.

The bioreactor contains natural elements such as wood chips, biochar and alum that work to filter nutrients from the water.

There also are several water testing wells and sampling ports to check for nitrogen and other chemicals to help determine the effectiveness of the project.

The goal of the yearlong project is to determine if the bioreactor can indeed assist in removal of nutrients, including nitrogen, before surface water flows from the bog and into the river and eventually the bay. Nitrogen overload is a major contributor to the region’s water quality issues and is responsible for toxic cyanobacteria blooms.

Dannhauser measures the water levels at the bioreactor three times a week and collects water samples weekly. The samples are sent every two weeks to an EPA laboratory in Oklahoma for testing.

“We are starting to learn things every single day,” Dannhauser said. “But we won’t have the big picture results for a while.”

Ideally, the project will yield a low-cost supplement to Barnstable’s municipal water treatment plan that can be used to help preserve water quality until sewers are built.

Barnstable is embarking upon a $1.06 billion sewer project that is expected to continue for the next three decades.

“If it really works, maybe we can save the town some money,” Dannhauser said. “We can put (bioreactors) in all the ditches of this cranberry bog and in cranberry bogs across Cape Cod.”

Follow Geoff Spillane on Twitter: @GSpillaneCCT.