~ Eklutna Lake ~
Anchorage’s predominant drinking water source is Eklutna Lake at 835 feet above sea level in the Chugach State Park. Glaciers cover the mountain peaks above the lake at an altitude of 6,000 feet. The lake is 6.5 miles long, with 16 miles of shoreline. The lake’s average depth is 120 feet with a maximum depth of 200 feet and maximum width of 1.1 miles.
Ship Creek provides Anchorage with an abundant and reliable secondary source of drinking water within its 90 square mile watershed, at elevations up to 5,100 feet.
In addition, Anchorage is fortunate to have several large underground aquifers. These deep, cold and naturally filtered underground pools of quality drinking water supply the Municipality with water during periods of increased demand or emergencies. From these aquifers, AWWU operates 12 active, high production wells. Nine smaller production wells operate in standby mode to supplement Anchorage, Eagle River and Chugiak in times of need. AWWU also operates independent water systems in Girdwood and Peters Creek.
Anchorage’s Drinking Water
The Eklutna and Ship Creek Water Treatment Facilities can produce up to 65 million gallons of water per day (mgd). Anchorage’s wells can combine for an additional 17.5 mgd. AWWU’s reservoirs can hold 60 million gallons of water. Approximately 810 miles of water mains crisscross the Utility’s distribution area.
In 2003, AWWU produced 9.4 billion gallons of drinking water. Eklutna Water Treatment Facility produced 8.1billion gallons, 85.8 percent of the total. Well production combined for 13.8 percent of the total, or 1.3 billion gallons, and at Ship Creek .5 percent was produced, or 42.6 million gallons. Average daily water production was 25.9 million gallons.
To achieve greater operational efficiency, production of water from Ship Creek serves in a backup role most of the year for overall water distribution. During the summer months when business and residential water demand increases, Ship Creek is operated to meet increased customer demand.
~ Eklutna Water Treatment Facility ~
To
achieve greater operational efficiency, the Ship Creek facility serves in a
backup role most of the year for overall water production. During the summer
months when business and residential water demand increases, Ship Creek is
operated as a peaking facility to meet increased customer demand.
The Eklutna Water Treatment Facility produces water from the Eklutna Lake watershed, 119 square miles within the Chugach State Park. This Facility is designed to double its daily water production from 35 mgd to 70 mgd when demand requires it.
Eklutna Lake is an exceptional source of raw water. The water exceeds almost all water quality standards prior to treatment. It is moderately soft with a pH range between 7.5 - 8.4.
Turbidity levels range from 0.1 to 62 Nephelometric Turbidity Units (NTU). Turbidity is a measure of cloudiness in the water. Raw water turbidity is measured to help determine levels of treatment. High turbidity occurs during the spring and summer when snow, ice and glacier melt are the major sources of incoming lake water.
Drinking water, including bottled water, may reasonably be expected to contain minute amounts of some contaminants. The presence of these contaminants does not indicate the water poses a health risk. More information about contaminants and potential health effects can be obtained by calling the Environmental Protection Agency's Safe Drinking Water Hotline, 1-800-426-4791.