An all-to-common occurrence in annual reports dealing with water quality in the Colorado City/Rye area indicates that levels in the drinking water of Trihalomethanes (TTHM) and Haloacetic Acids (HAA5) that exceed the accepted state standards.
The accepted EPA (Environmental Protection Agency) standard for TTHM is 80 parts per billion. The accepted level on HAA5 is set at 0.060 milligrams per liter.
Something to be mindful of, however, is that samples are required to be taken every quarter and then a four-quarter rolling average is used to come up with the appropriate number. Because both of these issues are worse during times when the water source has a large number of plants in the water source (ground water), one quarter can be out of compliance by a large enough amount to make it an entire year before the number assigned falls into an acceptable level.
Levels normally vary within a single water supply depending on the season, water temperature, amount of natural organic matter in the water, pH, amount of chlorine used, time in the distribution system and other factors.
So how dangerous are these compounds?
All public water is contaminated to some level. This chemical occurrence is the norm for most cities or municipal water supply. Especially if ground water is the primary source of the water system (Jim Eccher and Pure Home H2O), THM is quite common and includes chloroform, dibromochloromethane, bromodichloromethane and bromoform.
The chlorine that we are required to put in our water causes a reaction with natural organic matter that produces TTHM’s.
Haloacetic acids are also byproducts that occur during the chlorination of water. These byproducts form when the chlorine used to disinfect water reacts with organic matter. The most common haloacetic acids in drinking water are monochloroacetic acid (MCA), dichloroacetic acid (DCA), trichloroacetic acid (TCA), monobromoacetic acid (MBA), and dibromoacetic acid (DBA).
The official position is that haloacetic acids have low toxicity and are not likely to cause harmful effects at the levels commonly found in drinking water. That said, people who are exposed to high levels of haloacetic acids in their drinking water sometimes appear to have an increased risk of getting cancer over time.
Why don’t we simply stop chlorinating our drinking water? Without adequate disinfection of our water supplies, the health risks from micro-organisms would far outweigh the risks from these bacteria. Drinking water is disinfected with chlorine to kill bacteria and viruses that can cause serious illnesses and deaths. In fact, chlorination of drinking water is one of the greatest achievements of public health protection having virtually eliminated typhoid fever, cholera and many other diseases.
The most effective way, by far, to reduce the levels of haloacetic acids in water is by removing their organic precursors. Conventional water treatment – coagulation, sedimentation, and filtration – reduces the quantity of organic matter in the water, but sometimes it is not enough.
The Colorado City Metro District is also working on a Dissolved Air Filtration (DAF) which will have to be included in the design of the Lake Beckwith dam project as to a footprint for the inlets and outlet to the plant for consideration. The DAF system attacks the organic matter in Lake Beckwith which greatly lessens the organic material in the lake and reducing material for chlorine to interact with.
The leading belief is that long term exposure to high levels of these bacteria can cause cancer. However, the only studies into the toxicity of these bacteria involve animals – not humans.
In experiments conducted on mice, mice exposed to high levels were more likely to develop liver cancer. Since humans were not studied, no one can guarantee the effects of drinking water containing unsafe levels of these disinfection byproducts.
There are some simple things that can be done to reduce risk. In a study by the State of Massachusetts they developed several commonsense approaches to reducing whatever concerns the materials may cause.
Water can be left overnight in a pitcher to allow the chemicals to leave the water. Most are volatile and will easily evaporate from the water at room temperature.
Ventilating the bathroom when bathing or showering and reducing the length of showers and baths can be a help as can room exhaust fans in bathrooms. Limiting time spent in or around chlorinated pools or hot tubs.
Although bottled water studies in recent years have shown their own set of health risks, bottled water that meets federal drinking standards is another option for reducing HAA5 and TTHM in drinking water.