Tuesday, August 25, 2009

Scottsdale water update for NIBW residents

For those of you who don't know - NIBW is the acronym for the "North Indian Bend Wash" Superfund site. Info at the link.

The following is an email from Vicki Rosen, the EPA's Community Involvement Coordinator for NIBW -


This note is to let you all know about an external water leak that occurred last Thursday, August 20, at the Scottsdale Central Groundwater Treatment Facility (CGTF). As you know, the facility uses a "pump and treat" system to treat groundwater contaminated primarily with trichloroethylene (TCE) from the NIBW site. The CGTF is operated by the City of Scottsdale, including its four extraction wells.

Here's what happened according to a phone call we received from the City of Scottsdale:

First, and most importantly, the City reported that the leak was not associated with the drinking water system.

At approximately 7:00 am on August 20, an employee at the Coronado Golf Course noticed a water leak and advised the City. When City employees arrived at 8:00 am, they found that it was coming from an air release valve on a water line connected to one of the extraction wells (S71). City staff immediately shut down valves upstream from the leak to stop the flow of water in addition to the associated well. The leak originated at a coupling between the water line and the air release valve. The water flowed into an irrigation ditch which feeds into a lake on the golf course.

Here's what the City reported was done to address the leak:

- The City followed the EPA-approved Contingency and Emergency Response Plan

- The coupling between the air release valve and the water line was repaired and back in operation by 10:00 am the same day

- The City inspected all air release valves on all the pipelines as a preventative measure and repaired any that were of concern

- Water samples were collected at several locations including the point where the leak originated, a ditch that received the runoff and two locations at the lake on the golf course (where water enters the lake and where it exits)

- A soil sample was taken at the location of the leak

Here's what else the City reported to us:

- It's estimated that 200,000 gallons of groundwater leaked onto the ground

- Initial sampling results show TCE at 65 parts per billion at the point of the leak and non-detect at the ditch and the lake

- The City initially cordoned off the area of the spill to discourage public access until there was no concern

What happens next?

The City is in the process of preparing a report detailing the incident and corrective actions. I will share this report with all of you after we receive it.

Again, please note this leak occurred on the delivery side of the system conveying untreated water to the treatment facility and had no impact on the drinking water system.

I've attached a flyer from the City that is going to residents adjacent to the golf course where the leak occurred.

On another note, I know we haven't met in quite a while.

There are several reasons for this, one being that we've been waiting for the most current information on site activities that would be of interest to the community. Due to a very full schedule I have for the next few weeks, we may not be able to get together before November but we'll do the best we can. Our dear project manager, Jamey Watt, is on a detail in Honolulu (poor guy). Taking over for him at the NIBW site is Rachel Loftin, a very experienced remedial project manager. We're looking forward to getting together with all of you.



I've got to head downtown for the legislative session, so I won't be able to look into this until later today or sometime tomorrow.

BTW - Arizona American Water, the company that has had so many problems with the facility that they operate to treat a portion of the contaminated groundwater before selling it to users in parts of Scottsdale and Paradise Valley, is under investigation by ADEQ for the way that it has handled drinking water supplies in western AZ.


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