Mexel and CWA 316(b) Intake Compliance


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Overview – EPA has developed regulations under Section 316(b) of the Clean Water Act requiring that the location, design, construction and capacity of cooling water intake structures reflect the best technology available (BTA) for minimizing adverse environmental impacts (AEI). More than 1,500 industrial facilities using large volumes of cooling water from lakes, rivers, estuaries or oceans to cool their plants will be subject to the 316(b) regulations.

The 316(b) rules were developed because cooling water intake structures can adversely impact aquatic life by pulling large numbers of fish and shellfish or their eggs and juveniles into a power plant’s or factory’s cooling system. There, the organisms may be killed or injured by heat, physical stress, or the chemicals used to maintain the cleanliness of the cooling system. Larger organisms may be killed or injured when they are trapped against screens in front of an intake structure (“impingement”). Smaller organisms or eggs or juvenile forms of some species can also be damaged or killed as they are entrained in the rapidly moving cooling water inside the cooling system (“entrainment”).

Entrainment – Mortality associated with entrainment comes from many factors and is highly site-specific. Mexel can be an important part of a 316(b) compliance plan to reduce the adverse environmental impacts to the BTA level. Once the organisms currently lost to entrainment are estimated and the most sensitive species identified, Mexel can be evaluated for use as an alternative chemical treatment to improve survival of the target species for that location. Mexel’s lower toxicity, compared to most chemical treatment programs, reduces entrainment mortality from chemical stresses and can be paired with operational measures and some mechanical devices for a highly effective 316(b) program.

Impingement – Fish loss is also the result of multiple factors including chemical exposure, physical damage or death from impingement on the screens, and even from the mechanical systems designed to return live fish to their environment. Mexel’s very low toxicity to fish means less additional stress on organisms, thus improving survivability for some impinged species, and achieving the 316(b) targets.

Detailed biodiversity studies on Mexel 432/0 have been conducted over a period of more than 10 years. The results demonstrate no adverse effects on biodiversity from the product, another positive consideration in 316(b) planning.

For more information on Mexel’s low toxicity and ability to maintain biodiversity click here!