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Lack of Backflow Prevention Allows Lethal Pesticide to Contaminate Water

Updated: Oct 9, 2018

Paraquat Holding Tanks
Paraquat, a lethal Pesticide, was held in storage tanks connected to a town water supply, caused the drinking water for 63 homes to be contaminated

The incident drew widespread attention and made the local newspapers. It was the lead story on the ABC news affiliate in Washington, D.C. and virtually all the Washington/Baltimore newspapers that evening. The news media contended that lethal pesticides may have contaminated the water supply and among the contaminants was paraquat, a powerful agricultural herbicide.

The investigation disclosed that the water pressure in the town water mains was temporarily reduced due to a water pump failure in the town water supply pumping system. Coincidentally, a gate valve between a herbicide chemical holding tank and the town water supply piping had been left open. A lethal cross-connection had been created that permitted the herbicide to flow into the potable water supply system. Upon restoration of water pressure, the herbicides flowed into the many faucets and outlets of the town water distribution system. This cross-connection created a needless and costly event that fortunately did not result in serious illness or loss of life. Door-to-door public notifications, extensive flushing, water sample analysis, and emergency arrangements to provide temporary potable water from tanker trucks all contributed to an expensive and unnecessary town burden ( -

This incident had to be complete nightmare for the water utility. However, it could have been prevented if a backflow device was required at the water supply to the property where the herbicide chemical holding tank was located. Yes there might have been some additional cost that the Water Utility would have had to place on the property owner, but think about the trouble they would have saved themselves if that work had been done upfront. The utility did the right things through the notifications, pipe flushing, water analysis, and provision of potable water, but the article does not discuss what that cost was. In the end, all of the customers within that water Utility service area are going to have to foot that bill.

Backflow incidents like this, unfortunately, have happened many times throughout different parts of our country. Refer to our article Backflow Incidents that Could’ve Been Prevented to read about more unfortunate Water Utilities and situations they, and their customers, have had to deal. Luckily this incident did not cause any people to become ill, or worse, die. However, it definitely causes people to question the safety of their potable (drinking) water. Additionally, may folks start to question if the public officials in charge of the water department are doing a good job or not. If Water Utilities affected by situations like this have backflow management programs in place that are properly maintained, then they have something to point to showing they were proactively trying to prevent an occurrence like this from happening. Those that don’t have backflow management programs in place, and a backflow situation takes place that causes illness or death to their constituents, then they are just plain irresponsible, and in my opinion, unfit to operate a Water Utility.

Backflow Peventer

Some professionals in the water industry would argue that it is the property owner’s responsibility to install and maintain the correct backflow device, and I would agree with them. The cost of designing the backflow device installation, purchasing the backflow device, installing it, maintaining and testing the device, should fall on the shoulders of the property owner. However, ultimately the water purveyor (Water Utility) is responsible for the safety and quality of any water that is distributed through the system. Therefore, it is in the best interest of the Water Utility to require the proper backflow prevention devices at properties where dangerous elements could be introduced to the water supply.

One of the biggest challenges facing Water Utilities is the cost required to maintain a backflow management program. There are many systems, pieces of equipment, and technology that demand the attention of the Water Utility personnel. Their resources are certainly limited and many of them must operate on a shoe-string budget. Backflow management programs are a pure cost to the utility and they typically don’t receive any revenue from that facet of their business. That doesn’t mean the Water Utility has an excuse to not put a program in place or improve on the one that already exists! However, there are ways that Water Utilities can implement and maintain a backflow management program for little or no cost. Refer to our Article 10 steps to implementing and maintaining a backflow management program to learn how this can be accomplished.

I believe Water Utilities need to use the help of private industry now and in the future to accomplish everything necessary to operate and maintain their water systems. Third party backflow management programs are a great example of how Water Utilities can take advantage of this situation. Learn how VEPO CrossConnex can help your Water Utility start a backflow management program or operate and existing one more efficiently at little or no cost to your Water Utility by Requesting a DEMO. Don’t let your Water Utility be the next one with a negative story in the media. VEPO CrossConnex can work with you to be proactive in your approach to backflow program management whether you have an existing program that could use some improvement, or you do not currently have anything in place to track your backflow devices.


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