About The Program

NBC’s award-winning Pretreatment Program helps to protect the environment as well as human health.

Why is a Pretreatment Program necessary?

Discharging certain substances into the sewer system can:

  • interfere with the operation of the wastewater treatment facility (WWTF) by upsetting the biological process and killing the microorganisms needed for proper treatment
  • jeopardize the health and safety of NBC personnel
  • clog sewer lines
  • be extremely dangerous if dumped in high concentrations
  • mix with other chemicals to form toxic gases

WWTFs are not designed to remove heavy metals, cyanide and other toxic chemicals. Approximately 40 to 60 percent of these substances can settle out of the wastewater and into the sludge, contaminating it and preventing its reuse, while the remainder empties into Narragansett Bay and its tributaries.

Once this happens, marine life is exposed to toxic substances, which may enter the food chain and can eventually affect people. In addition, these toxics can prevent the NBC from meeting its effluent limits that are established by EPA and RI DEM.

To control toxic discharges at the source, the federal Environmental Protection Agency (EPA) requires that the NBC to implement a Pretreatment Program.

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What is a Pretreatment Program?
A Pretreatment Program permits, monitors and regulates a variety of industries in order to protect NBC treatment facilities and Narragansett Bay from the discharge of harmful contaminants.

Industries that are typically regulated are:
  • electroplaters, metal finishers
  • chemical manufacturers
  • machine shops
  • laboratories
  • hospitals
  • laundromats
  • restaurants
  • other firms that are tied into the NBC's sewer system

For more information on the history of Pretreatment Programs, please read EPA's National Pretreatment Program, 1973-2003: Thirty Years of Protecting the Environment.

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How effective is the Pretreatment Program?

To date, this program has had a major positive impact on the quality of treatment and discharges from the Field's Point and Bucklin Point WWTFs and has dramatically reduced the amount of metals and toxics being dumped into the sewer system and ultimately into Narragansett Bay.

For example, in 1981, local industries discharged 954,099 pounds of heavy metals and 80,440 pounds of cyanide to the Field's Point wastewater treatment facility. By 2008 significant reductions in metals (97%) and cyanide (97.5%) were achieved.  Because of these great metals and cyanide reductions the Providence and Seekonk Rivers have been removed from the EPA 303(d) list of impaired waters for toxics.

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