The Anne Arundel County Health Department cautioned residents yesterday to avoid swimming in or contact with the water in the upper portion of Weems Creek in Annapolis.
The agency issued a health advisory after more than 1,000 gallons of sewage spilled early yesterday morning into a tributary, behind the Admiral Heights subdivision.
Sewage backed up at a Bristol Road pumping station owned by the City of Annapolis during a electric power failure between 5 and 6 a.m., department spokeswoman Evelyn Stein said.
Stein said she did notknow the cause of the power failure. Officials with the Annapolis Department of Public Works,which operates the pumping station, could not be reached for comment.
The health advisory includes the portionof Weems Creek from Rowe Boulevard to the creek's headwaters.
Thesewage will be allowed to flush out of the creek naturally. Weems Creek is a Severn River tributary.
Stein said the health advisory will remain in effect until water-quality tests on consecutive days show fecal coliforms have dropped below 240 coliforms per 100 milliliters.
Fecal coliforms are bacterial colonies associated with human and animal wastes. Human wastes can carry diseases such as hepatitis and cause illnesses such as diarrhea.