The Army says a 1.8 million gallon overflow of partially treated sewage from a wastewater treatment plant serving Aberdeen Proving Ground's Edgewood Area earlier this month had minimal effect on the environment.
"In a report received [May 8] at APG's Environmental Division, test results from samples taken from King's Creek and Bush River May 2, indicated the wastewater overflow that occurred May 1, was diluted and mostly rainwater," the APG Garrison said in a news release Wednesday.
In addition to the samples that were tested, observations of both waterways and areas of the bay to which the water flows, no adverse effects to wildlife were observed, the release states.
The Army had previously reported the Edgewood Area of Aberdeen Proving Ground experienced a wastewater treatment plant sewage bypass and overflow caused by extreme rainfall totaling 5.6 inches in 24-hours between April 30 and May 1. The discharge from the plant along Kings Creek, a Bush River tributary, was estimated at 1.8 million gallons.
Lime was applied to the affected area and signs were posted indicating "No Fishing, No Crabbing, No shellfish harvesting, No Swimming, in the area until further notice."
Experts from APG's Edgewood area continue to monitor the affected area in case any further treatment is needed, the Army said in its latest update, noting that the Harford County Department of Health and the Maryland Department of the Environment were notified of the event.
The Army incident was one of three involving raw or partially treated sewage getting in to Bush River or its tributaries during or shortly after the heavy rainstorm that hit Harford County from the evening of April 29 through the morning of May 1.
Two sewage pumping stations operated by Harford County experienced overflows, the largest being 300,000 gallons of untreated sewage from the Bill Bass station in Edgewood between the afternoon of April 30 and the morning of May 1. About 200 gallons of untreated sewage were released from a smaller pumping station in Long Bar Harbor on April 30.
Like the Army, the county government said it reported the spills to Maryland health and environmental authorities and posted signs advising the public avoid contact with the waterways in the immediate vicinity of both facilities.