Flint, Michigan – January 5, 2015 – The City of Flint’s Department of Public Works has been actively working to address upgrades and repairs to the city’s water distribution system. These actions appear to have corrected several long time concerns with the system as well as known compliance issues with the system, including a recent temporary increase in the maximum contamination level (MCL) of trihalomethanes (TTHM) found in water samples collected from the system during a testing period which ended November 30, 2014. The public was notified of the violation as a precautionary measure as required by the Michigan Department of Environmental Quality (MDEQ).
TTHM is a common by-product of the water chlorination process. Increased levels in some water samples collected in the city were an indicator of weaknesses in the distribution system and treatment process, which were due to years of deferred repairs and upgrades to a very old system. The City of Flint’s DPW is and has been pursuing a comprehensive plan to make critical upgrades to its water distribution system for the long term health and operation of the system and to mitigate any future issues.
The levels of TTHM in the water were elevated marginally above the MCL in some samples, resulting in a less urgent “Tier 2” Environmental Protection Agency notification. This means that the EPA believes there is no immediate risk to consumers and/or the system may have already returned to acceptable levels by the time the notice was issued. Although TTHM is considered to be an environmental pollutant that can be carcinogenic, it can only be hazardous if consumed in water containing the elevated levels at a rate of two liters per person, per day for 70 years. The City of Flint wants to assure the public that according to the MDEQ the water is safe for drinking and all other purposes.
The City of Flint worked closely with the MDEQ to correct the issue by flushing hydrants and replacing key valves in the distribution system. These measures have shown to be effective in not only lowering the TTHM levels in the system, but have also improved the overall health of the system. The Michigan DEQ has acknowledged and appreciates the progress of the City’s preemptive evaluation of operations which identified the deficiencies and the corrective measures being taken. The latest round of testing has shown a significant decrease in levels across the board, with most samples falling well below the MCL. It is expected that all sample levels will be well below the MCL in the next round of quarterly scheduled testing in March of 2015.
Flint’s DPW welcomes the rigorous review of the MDEQ to ensure steady progress is made on this important issue. “Our proactive plan of replacing valves, flushing hydrants and making other adjustments to the system has shown both promising short term results as well as strengthening our water distribution capability in the long term,” said Flint DPW Director Howard Croft. Both the City of Flint and the MDEQ expect the corrective measures being implemented will resolve the issue by early 2015.
The improvements in MCL levels also mirror the increased consistency being seen in chlorine residuals, flow rates, and overall water quality within the city. As part of the DPW strategic plan and Capital Improvement Plan, there are additional improvements coming to the 600 miles of distribution main including, pipe replacements, leak detection, hydraulic modeling, and enhanced asset management features. The Department of Public Works will continue to provide public education and communication about the quality, the process, and the continual improvements occurring within the system as part of the overall management of the water system.