The Newport Water Division, which provides water to customers in Newport and Middletown and wholesale to Portsmouth and Naval Station Newport, announced that its drinking water has exceeded the permitted level of trihalomethanes.
A notice was sent to all customers.
Trihalomethanes are formed in drinking-water primarily as a result of chlorination of organic matter present naturally in raw water supplies, according to the World Health Organization.
The Newport Water Division routinely tests at various sites within the distribution system for disinfectant by products (DBPs). EPA sets standards for controlling the levels of disinfectants and DBPs in drinking water, including total trihalomethanes (TTHMs).
The average results of tests taken during the last four quarters show that the system exceeded the standard or maximum contaminant level (MCL), for TTHMs. The Environmental Protection Agency (EPA) standard for TTHMs is 80 parts per billion (ppb) for an annual running average. Newport Water Division’s average level of TTHMs for the last four quarters (July 1, 2012 to June 30, 2013) is 82.9 ppb.
The following FAQ was provided by the water division:
What does this mean?
This is not an emergency or immediate risk, according to the department. There are no actions that you need to take at this time. You do not need to use an alternate water supply. You do not need to boil your water or take other corrective action. However, if you have specific health concerns, consult your doctor.
Many water systems treat water with a chemical disinfectant, such as chlorine, in order to inactivate pathogens that cause disease. While disinfectants are effective in controlling many harmful microorganisms, they react with organic and inorganic matter in the water to form DBPs, some of which pose health risks at certain levels. Some people who drink water containing trihalomethanes in excess of the MCL over many years may experience problems with their liver, kidneys, or central nervous system, and may have an increased risk of getting cancer. The public health benefits of chlorine disinfection practices are significant and well recognized. Consequently, one of the most complex questions facing water supply professionals is how to reduce risks from disinfectants and DBPs while providing increased protection against microbial contaminants.
What is being done?
TTHMs are a group of volatile organic compounds (Chloroform, Bromoform, Bromodichloromethane, Dibromochloromethane) which form with time when the natural organics in water react with chlorine as it breaks down. Because of the source water quality in Newport’s reservoirs, removing the level of organics necessary to meet the TTHM standard, particularly during the warm weather months, is one of our greatest challenges. The length of time water remains in the distribution system, commonly referred to as “water age”, is also known to produce higher TTHM levels as the water gets older. A variety of engineered systems can be implemented to achieve a lower water age in the distribution system.
Newport Water has previously taken the following steps to lower TTHMs in your drinking water: (1) installed mixing systems in the Reservoir Rd and Goulart Lane water storage tanks which assists in reducing the water age in the system; (2) upgraded the Lawton Valley Sedimentation Basin #1. The sedimentation basins are the first process in the treatment plant which removes organics from the raw water supply; (4) installed aeration systems in the Lawton Valley and St. Mary’s Reservoirs. The aeration system has the potential to reduce algae blooms in the raw water supply, which can lead to higher organic levels in the treated water; and (5) treatment plant staff has performed adjustments to the chlorine dioxide pH levels in an attempt to better control DBPs in the system. This has been accomplished by using slightly less chlorine in the production of the chlorine dioxide, which will help reduce TTHM levels.
In January 2012 the City of Newport awarded a design build contract to the joint venture of AECOM – C.H. Nickerson for the Station No. 1 Water Treatment Plant Upgrade and the New Lawton Valley Water Treatment Plant Project. The value of the contract is $67,000,000.00. Prior to the award of the contract, Newport Water conducted detailed pilot testing to determine the optimal treatment method to reduce TTHMs. Based on the results of the studies, Newport Water is requiring advanced water treatment processes to be included in the improvements to the treatment plants in order to assure the sufficient level of organics removal in order to control TTHMs. Construction of the water treatment plant improvement projects began in September 2012 and is progressing on schedule to have the entire project completed and operational by December 2014.