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TCR Newspaper Notice

District of Columbia Water and Sewer System


Tests Show Coliform Bacteria in District of Columbia Water

Our water system recently violated a drinking water standard. Although this is not an emergency, as our customers, you have a right to know what happened, what you should do, and what we are doing to correct this situation.

We routinely monitor for the presence of drinking water contaminants. At the date that this notice was forwarded to the printer, the DC Water and Sewer Authority (WASA) has taken 245 samples for coliform bacteria during the month of September 2004. To date, 19 of the 230 samples (8%) that have completed testing showed the presence of coliform bacteria. The standard is that no more than 10 samples (5%) out of a required 210 samples may do so. WASA is publishing this notice ahead of the legal requirement to meet our pledge to keep our customers informed as soon as possible of any issues with respect to our water distribution system. Although WASA could have stopped sampling after the required 210 samples had been taken, WASA continues to sample without interruption to provide strong oversight of our system.

What should WASA customers do?

What does this mean to WASA customers?

This is not an emergency. If it had been you would have been notified immediately. Total coliform bacteria are generally not harmful themselves. Coliforms are bacteria, which are naturally present in the environment, and are used as an indicator that other, potentially harmful, bacteria may be present. Coliforms were found in more samples than allowed and this was a warning of potential problems.

Usually, coliforms are a sign that there could be a problem with the treatment or distribution system (pipes). Whenever we detect coliform bacteria in any sample, we do follow-up testing to see if other bacteria of greater concern, such as fecal coliform or E. coli, are present. We have not found any of these bacteria in our subsequent testing. If we had, we would have notified you immediately. However, we are still finding coliforms in the drinking water.

WASA, as well as the District of Columbia Department of Health and the EPA have found that a public health emergency does not exist as a result of these findings. It is believed that these readings are the result of the bacterial film, or "bio-film", which exists in almost every water distribution system, detaching from pipe walls. The addition of orthophosphate to the distribution system is also likely contributing to increased occurrence of coliform bacteria in water samples. The orthophosphate addition was approved by the USEPA to help reduce lead in tap water. This bio-film detachment is sometimes seen during the early part of orthophosphate treatment. Orthophosphate can be beneficial to the system in the longer term by helping to reduce overall bacteria levels in the water mains.

We will inform you when our sampling shows that acceptable levels of bacteria are present. We anticipate this issue will be resolved within several months, but a specific date cannot be predicted at this time. WASA and the Washington Aqueduct are addressing the issue by:

The DC Water and Sewer Authority and the US Army Corps of Engineers bring your drinking water to you as a cooperative effort. The water is initially treated by the Washington Aqueduct Division of the Corps, and then delivered to your tap via the distribution system maintained by WASA. For more information , please contact WASA at 787-2732 or by email WQP2003@DCWater.com or by writing to Mr. Richard Giani, WASA Water Quality Division, 301 Bryant St. N.W., Washington, D.C. 20001.

Please share this information with others who drink this water, especially those who may not have received this notice directly (for example, people in apartments, nursing homes, schools, and businesses). You can do this by posting this notice in a public place or distributing copies by hand or mail.

The DC Water and Sewer Authority is sending this notice to you.

Public Water System ID#: DC0000002

Date distributed: 10-4-04


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