From Harford County government:
The Harford County sewer system was significantly affected by the heavy rain and flooding conditions that plagued the County throughout the day on Thursday. Rainfall totals estimated at over 8-inches throughout the service area and severe flooding of the major stream valleys resulted in high flows in the County sanitary sewer system. Rainfall and flooding resulted in infiltration and direct inflow of storm water into the sewer system. The impact of the storm water more than tripled our normal flows in the system as measured at our main wastewater treatment plants.
Despite the high flows and adverse conditions, the impact to the environment from the County sewer system was relatively minor with just one significant sewage spill at a County sewage pumping station. Another sanitary sewer overflow is believed to have occurred along the Bynum Run between Wheel Road and Ring Factory Road based on metered flow records but the actual overflow could not be verified or quantified due to the flooding of the Bynum Run.
The pumping station spill occurred at the County’s Bill Bass sewage pumping station in Edgewood located adjacent to the Bush River. High flows to the station were slightly more than the three 250 hp pumps could move through the system. County W&S crews whowere on duty and in “storm response mode” responded quickly to the alarm condition which started at approximately 10:00 a.m. Both County owned and contracted tanker trucks were mobilized to the site to reduce the amount of the overflow.
The spill was stopped at approximately 2:00 p.m. An estimated 7,650 gallons of diluted sewage was spilled into Bush River but through the use of tanker trucks a major portion of the flow that would have spilled into the river if not for the use of the tankers was avoided. The tankers pumped over 50,000 gallons and hauled the sewage to another part of the County system where it was able to flow to the Sod Run WWTP for treatment.
The spill was reported to Maryland Department of the Environment and to the Harford County Health Department. The site has been posted with warning signs and the public is advised to avoid contact with the water in the area. The Health Department ordered the signs to remain in place for 30 days. The impact of the spill is mitigated by the dilution of the storm water both in the sewer and in the River.
Regrettably sewer overflows are practically unavoidable under some circumstances such the severe rain storm. However, Harford County was exceptionally fortunate that the storm resulted in relatively minor overflows.
Prior to the storm all equipment was in a high state of readiness and throughout the storm most all equipment operated as needed. In total, County W&S pumped and hauled over 215,000 gallons of sewage from various stations throughout the event to avoid and mitigate sewage overflows.