A group committed to tackling the nitrogen problem in Wareham's waterways is calling for the town to sewer more neighborhoods.

The Wareham Nitrogen Consensus Group recently announced its five priorities for the next six months, which include asking the town to develop a new "Comprehensive Wastewater Management Plan" for reducing nitrogen in wastewater.

"The group believes expanded sewering is the most important step this town can take to reduce nitrogen pollution," the group wrote in a letter addressed to residents, "and there is a need to research alternative options for financing this sewering."

Reducing nitrogen pollution was a primary goal of the recent expansion of the town's sewer system. A Wastewater Management Plan completed in 2002 identified seven "needs areas" that the town should sewer to reduce nitrogen pollution.

The problem with nitrogen, which is naturally present in human waste and found in fertilizers, is that it makes things grow. When nitrogen pollutes waterways, invasive species such as algae grow out of control and use up the oxygen, which in turn causes fish, shellfish, and other marine life to die.

Financing the sewer expansion is up to the residents of the neighborhoods being sewered, which has left property owners with tens of thousands of dollars in "betterment" fees, calculated by dividing the total cost of a sewer project by the total number of households in a neighborhood.

Residents of the last of the neighborhoods identified in the 2002 plan still do not know how much they will have to pay.

A project covering the Cromesett and Oakdale areas is nearly complete, and residents have been protesting the more than $20,000 betterment fee estimated for the project.

A sewer project in the Agawam Beach and Mayflower Ridge neighborhoods was put on hold, after public outcry over predicted construction costs, which may have put an estimated $35,000 betterment fee on the backs of those residents.

Betterment fees for other recent projects have ranged from $12,000 to $17,000.

The Wareham Nitrogen Consensus Group, a partnership of the nonprofit Buzzards Bay Coalition and interested stakeholders — including cranberry growers, town officials, and concerned citizens — released the "Wareham Nitrogen Consensus" in 2010. The document is a 41-page action plan that contains recommendations to clean up the nitrogen in Wareham's waterways.

The group recently discussed its progress on the action plan, and examined "where we need to do more," explained Rachel Jakuba, Buzzards Bay Coalition vice-president for advocacy. The group announced its five priorities following that meeting.

The Buzzards Bay Coalition will continue to monitor all of Wareham's estuaries for water quality. The Coalition, Cape Cod Cranberry Growers' Association, Marine Biological Lab, Town of Carver, and the UMass Cranberry Experiment station will continue to partner in studying the nutrient releases from cranberry bogs.

Though calling for more sewering, the consensus group is also concerned about nitrogen entering the waterways through septic systems. The group is asking the Board of Health for an update on its regulations, which it has been crafting for more than a year.

An initial proposal that would have required that pricey "denitrification" septic systems be installed for all newly-constructed homes was scrapped earlier this year.

Jakuba noted that the Coalition has been providing the Board of Health with information as the board continues to draft regulations.

The Nitrogen Consensus Group is also advocating for the completion of the Massachusetts Estuaries Project report for the Wareham River. The project was launched in 2002 and intended to collect and analyze available data about nitrogen pollution in Southeastern Massachusetts and on Cape Cod. The Wareham River report was initiated in 2003, but has been delayed.

The group is also discussing the need for greater community-wide education about nitrogen.

Jakuba noted that Wareham is one of few communities where people are coming together to take on the nitrogen issue.

Citizens in Wareham "are really digging into the [nitrogen] problem and trying to figure out how to solve it," Jakuba noted. "We're hoping that change is going to come out of it."