At this week’s Stafford County Board of Supervisors meeting, the National Association of Clean Water Agencies gave “peak performance awards” to operators of the Aquia and Little Falls Run wastewater-treatment plants.

While the two plants seem to be in good working order, the past year hasn’t been as good for the county sewer system.

Since August 2014, nine spills from the system have sent more than 1.5 million gallons of sewage into tributaries of the Potomac and Rappahannock river basins, according to Virginia Department of Environmental Quality reports.

The DEQ fined the county $36,400 for the spills.

The most recent incident happened on Monday, Aug. 24, when 27,000 gallons of sewage spilled from a pump station into Falls Run, a tributary that flows into the Rappahannock River near the Falmouth Bridge.

Fearing possible E. coli contamination, officials posted warning signs and closed the Historic Port of Falmouth Park, Old Mill Park and the City Dock, all of which are downstream of the point where Falls Run feeds into the river.

Samples were taken from the Rappahannock to see if the water was contaminated. Three days later, the parks were reopened after the results showed the river water met state standards for safe swimming, Stafford said in a report to DEQ.

Mark Miller, with the DEQ’s Northern Regional Office’s pollution response department, said there were no reports of fish kills following the most recent spill, so the department doesn’t believe aquatic animals were impacted.

Sewage system leaks are something all localities contend with, Miller explained. He added that the past year’s sewage spills in Stafford amount to a small percentage of wastewater that flows through such systems, which can handle 20 million to 30 million gallons each day.

The amount of sewage spilled in the past year amounts to less than 1 percent of the 2.486 billion gallons processed in Stafford during that time, according to county spokeswoman Shannon Howell.

Chris Moore, a senior scientist with the Chesapeake Bay Foundation, also said aging wastewater treatment infrastructures are an issue beyond Stafford.

“A lot of localities are dealing with this problem,” he said.

The Hampton Roads region, he pointed out, was forced to enter into a consent decree with the state to fix its wastewater treatment system.

The key is what is being done to fix the problems, said Moore.

Stafford has a dozen projects in the works or planned in an effort to upgrade the wastewater-treatment system.

The projects include the replacement of five pump stations. The county also is replacing sewer lines, including 4,400 feet of deteriorated line along U.S. 1 in North Stafford.

Moore said sewage leaks are just one of several sources of pollution impacting rivers in the Chesapeake Bay watershed.

He pointed to nutrient pollution from urban and rural development and agricultural operations as a longtime problem that now seems to “be heading in the right direction.”

Moore said sediment buildup, particularly in the Rappahannock River, also is a problem.

The DEQ lists the Rappahannock River as an impaired waterway from above the Interstate 95 bridge to the mouth of the Chesapeake Bay in Middlesex County.

The impairment is related to PCB contamination. PCBs are chlorinated hydrocarbons, manmade organic chemicals that can cause cancer and other health problems, according to the Environmental Protection Agency.

PCBs can leach into fish tissue. Because of that, the Virginia Health Department suggests limiting the consumption of American eel, blue catfish, carp, channel catfish, croakers, gizzard shad and stripped bass caught in the Rappahannock.