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PA DEP Orders Aliquippa to Address Secondary Contaminants in Drinking Water




Lauren Fraley, DEP



PA DEP Orders Aliquippa to Address Secondary Contaminants in Drinking Water


Pittsburgh, PA – The Pennsylvania Department of Environmental Protection (DEP) today issued an administrative order to the Municipal Water Authority of Aliquippa (MWAA) for drinking water violations. MWAA is a public water system that sources its water from groundwater wells and serves 6,575 metered connections in Beaver County.


In September 2019, DEP received two complaints of “dirty” or brown water, which could indicate the presence of iron and/or manganese.


Iron and manganese are classified by the U.S. Environmental Protection Agency (EPA) as secondary contaminants because their presence in drinking water primarily affects the aesthetics of the water, such as taste, color or odor.


EPA established a health advisory level (HAL) of 0.3 mg/L for manganese. EPA’s National Primary Drinking Water Regulations also established secondary maximum contaminant levels (sMCL) of 0.3 mg/L for iron and 0.05 mg/L for manganese. Health advisories and sMCLs are not enforced under the EPA; however, Pennsylvania enforces sMCLs. State regulations do not require public water systems to routinely monitor for secondary contaminants, but the regulations require systems to meet those standards and to take investigative or corrective action if exceedances occur. While it is not uncommon for iron and manganese levels to change as the source aquifer changes seasonally or over years, treatment should be sufficient to address such fluctuations.


As part of DEP’s investigation into public complaints, the department and MWAA — using EPA-approved methodology — sampled various points throughout Aliquippa’s distribution system in October and November 2019, and had the samples analyzed at state-certified laboratories. MWAA also began flushing its lines, a practice the system plans to continue three times a year to reduce water age and flush out scale and sediment from the distribution system. All recent samples were below the sMCLs. From late October to mid-November 2019, DEP received several more citizen complaints.


“Pennsylvania citizens are a critical part of our compliance program, as they are most acutely aware of what is happening in their community and are the eyes and ears between DEP inspections,” said DEP Southwest Regional Director Ron Schwartz. “Aliquippa residents not only notified the authority, they also reached out to DEP.”


DEP also conducted a review of its records and MWAA’s past compliance, during which DEP discovered that MWAA’s materials evaluation and lead and copper sample site plan did not meet the requirements of the regulations.


Public water systems like MWAA are required to review various sources of information to evaluate the composition of their distribution system (e.g., PVC, lead, copper, galvanized steel) to identify the highest priority sites for lead and copper sampling. These sites are classified as tier 1, 2, or 3 sites, with tier 1 sites representing the highest potential for lead or copper. MWAA’s submitted sampling plan identified only tier 3 sites to be sampled.


DEP’s order requires MWAA to do the following:


  • Submit a revised sample site plan that includes an adequate materials evaluation and appropriate sample site locations;
  • Initiate six-month monitoring for lead and copper at 60 sample site locations;
  • Monitor for manganese and iron on a weekly basis at the entry point of the distribution system and monthly at 10 sites within the distribution system using a DEP-certified laboratory;
  • Report exceedances of the HAL for manganese to DEP within one hour; and
  • Submit an application for the construction of a new water treatment plant.


MWAA previously notified DEP that it intends to upgrade its treatment facility. This order sets a strict timeframe for MWAA to submit the necessary application, correct errors in its identification and selection of sample sites and conduct additional sampling.


“It is DEP’s priority to restore confidence and address the concerns of MWAA customers through increased monitoring and reporting and treatment upgrades,” said Schwartz.


Customers are reminded to report issues of concern to DEP and to the public water system that supplies their drinking water. 






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