In 2004, high concentrations of nitrate in groundwater in the southern Willamette Valley prompted the state Department of Environmental Quality to declare a “groundwater management area” between Eugene and Albany.

A new report by the Oregon State University Extension Well Water Program recommends actions that could reduce nitrate from residential water sources in the area.

The southern Willamette Valley is only the third groundwater management area to be designated in Oregon (the other two are in Hermiston and Ontario). Since the designation, a citizens’ advisory committee appointed by DEQ has been working on a plan to reduce the amount of nitrate entering the groundwater.

“The nitrate in our groundwater comes from many different sources — fertilizers and septic systems are probably the top two, but there are also other contributors,” said Gail Andrews, an OSU Extension water-quality specialist.

Andrews led a group to look at ways that nitrate could be reduced from residential areas. Other groups addressed agricultural and commercial-industrial contributions of nitrate.

The OSU Extension Well Water Program, coordinated by Andrews, produced the Residential Working Group Report, which recommends ways to lower the groundwater nitrate from residential lawn and garden activities, septic systems and wells.

The report, which is available online, suggests actions that organizations and agencies might take to reduce nitrates, such as increasing public outreach; developing incentives or financial assistance; and examining regulations to make sure that they are consistent.

“The nitrate from any one source probably wouldn’t make that much difference, but when all of the inputs from all of the different sources over the years are all added together, we end up with more nitrate in some wells than is considered safe to drink,” Andrews said.

Andrews stresses that research about safe levels of nitrate in drinking water has not yet produced clear results. Older research has linked nitrate with a rare type of blue-baby syndrome, and some new research suggests possible links to adult illnesses.

The EPA standard for public drinking water was set at 10 parts per million to protect infants. However, there are no nitrate standards for individual household wells.

The Residential Working Group Report will be presented to the Groundwater Management Area Committee at its meeting at 8 a.m. Thursday in the Harrisburg City Hall.

The recommendations from all of the working groups will be combined into a formal action plan due to be completed by May 25.

The Residential Working Group Report can be viewed at http://groundwater.oregonstate.edu/willamette.

In addition, the OSU Well Water Program offers classes on proper care of wells and septic systems that include tips on preventing contaminating the groundwater that supplies your drinking water. Free classes will be held May 11 at OSU Extension Service offices in Albany and June 14 in Eugene. Screening of well water for nitrate is part of the class.

OSU Extension also offers free nitrate screenings and individual consultations at Well Water Clinics throughout the area. The next clinics will be May 20 at the Corvallis Farmers’ Market.