Quality of drinking water exceeds standards
June 22, 2010
By Warren Kagarise
Issaquah tap water exceeds water-quality standards set by state and federal regulators.
Officials announced the findings in the annual water-quality report issued June 16, and mailed the report to residents in early June.
The city purchased and produced 751.1 million gallons of drinking water last year. Issaquah customers used 693.4 million gallons of water during the same period.
City customers use water drawn from the Lower Issaquah Valley Aquifer. The city has four wells to the underground water source — a pair in the northeastern part of the city and another pair in the northwestern part. The wells vary from 100 feet to 400 feet deep.
The municipal water utility does not supply water to all Issaquah residents. Bellevue supplies water to Greenwood Point and South Cove customers, and the Sammamish Plateau Water & Sewer District supplies some North Issaquah customers.
The city also purchases water from Cascade Water Alliance — a regional group — to supply customers in the Issaquah Highlands, Lakemont and Montreux neighborhoods. Water purchased from the alliance has been fluoridated.
Otherwise, city water has not been fluoridated, with the exception of the Talus urban village. The pump station serving the community has a fluoridation system.
The city does not mix purchased and well water; separate distribution systems handle each.
In order to determine water quality, the city collected hundreds of samples last year to test for contaminants, such as harmful bacteria, arsenic and lead.
City Water Operations Manager Greg Keith said samples from groundwater sources vary little, if at all, from year to year.
Cryptosporidium, a microbial parasite, exists in surface water sources. Filtration removes the organism, but the most common methods cannot guarantee 100 percent removal. The infection caused by the parasite can lead to nausea, diarrhea and abdominal cramps.
EPA rules do not require groundwater sources, such as the Lower Issaquah Valley Aquifer, to be tested for cryptosporidium.
Samples taken at Cascade Water Supply surface-water sources last year did not detect the microbe.
The city also used the annual report as a way to remind residents to conserve water.
Resource Conservation Coordinator Micah Bonkowski said City Hall works with the water alliance to alert utility customers to rebates for water-efficient appliances and toilets.
Bonkowski said he also works to disseminate information about water conservation to Issaquah residents.
Warren Kagarise: 392-6434, ext. 234, or firstname.lastname@example.org. Comment at www.issaquahpress.com.