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Corrosion Control

A stack of corroded plumbing pipes
Environment, Great Lakes, and Energy

Corrosion Control

The Lead and Copper Rule (LCR) as a whole is designed to detect corrosion issues-the leaching of lead or copper into the water from pipes/fixtures in the system. This leaching can be reduced by several methods including the application of corrosion control treatment (CCT), which coats pipes over time to form a protective scale. 

After Benton Harbor's first ALE in October 2018, EGLE used its regulatory oversight authorities-in consultation with the EPA and technical experts-to support the city in responding more expeditiously and comprehensively on corrosion control than required by the LCR.  

  • EGLE directed the city to move forward immediately to install CCT. That treatment commenced on March 25, 2019, less than six months after the first ALE was validated. If the series of steps laid out in the LCR had been followed without this accelerated action, it could have taken up to 30 months for the supply to begin installation of CCT.   
  • EGLE required the city to conduct a corrosion control study, in addition to directing it to proceed with CCT. In other words, EGLE guided the city to take a "both/and" approach when the LCR generally gives water supplies an "either/or" choice.  
  • EGLE ordered the city to undertake enhanced monitoring so it could track the effectiveness of the CCT in reducing lead levels in the drinking water.

EGLE Drinking Water and Environmental Health Division (DWEHD) efforts to support Benton Harbor in implementing that approach from October 2018 (when the ALE was validated) through March 2019 (when CCT commenced) included:  

  • Guiding the city in securing EGLE regulatory approval for the CCT chemical feed system and approving the use of EGLE funds from the Lead Pilot Grant to secure the necessary equipment, chemicals, and labor to install the approved treatment;  
  • Providing the city onsite technical assistance in meeting new requirements to collect water samples from sites in the distribution system. This involved training city personnel in proper sample collection and using a state-owned pH/temperature probe in that process.  
  • Successfully advocating for Benton Harbor and its engineering consultant to adopt a higher target dose of total phosphate than they originally considered necessary. 
  • Confirming that the planned treatment strategy in Benton had proven effective for other water systems with similar source water. 

In the two-plus years since Benton Harbor first installed CCT in March 2019, EGLE has worked with the city, expert technical consultants, and EPA to monitor its application and impact. This has involved: 

  • Directing Benton Harbor to change the chemical blend and increase the target dosage of total phosphate in February 2020 based on review of data from the enhanced 2019 sampling; and   
  • Taking action when weekly sampling showed that the city was not meeting targeted levels of corrosion control chemicals in its distribution system, including revoking the certification of Benton Harbor's Operator-in-Charge who, among other problems, was unable or unwilling to address that deficiency despite repeated reminders from EGLE.  

The new Benton Harbor operations team in place now has adjusted phosphate rates. Weekly sampling consistently shows that the system is meeting the CCT goals designated by EGLE. The upcoming results from the current round of LCR monitoring will provide another data point for assessing the effectiveness of the CCT.  

To bolster the degree of confidence in Michigan's approach to corrosion control, EGLE recently announced the formation of a corrosion control work group of external experts to review the latest science and validate the best practices for Michigan communities to apply. As Michigan continues to implement its stronger LCR and ramp up service line replacement, that validation will provide valuable extra assurance the state is proceeding in a protective manner.