Portland Drinking Water Bull RunSource primary drinking water
Portland Drinking Water
Bull Run--Source • primary drinking water supply for Portland • Located 26 miles from downtown Portland in Sandy River basin, in Mt. Hood National Forest
Drinking Water • • Protected in 1892 for Portland drinking water supply Serves more than 900, 000 residents in the Portland 2001: protection boundary extended by federal law Groundwater available as a back-up supply since 1986 – used to meet peak water demand during summer months – emergency source of supply when Bull Run is not available ie. during Feb 1996 flood, used to meet water demands for several days due to turbidity in Bull Run reservoirs
• Turbidity: measure of how much sediment is in water • Groundwater: underground in soil, aquifers, springs, etc.
The Bull Run Watershed • 102 square-mile area • water from rain and snowmelt that flows to the Bull Run River and tributaries • river drains into two reservoirs -- more than 17 billion gallons stored
Powell Butte
Powell Butte • reservoir can hold 50 million gallons of water • In 1925, the Portland Water Bureau purchased Powell Butte for $135, 000 as a site for future reservoirs. • In 1981 the first reservoir was installed. • In 1990, Powell Butte Nature Park , the second largest in the city, was dedicated.
Mt. Tabor & Washington Park Storage Reservoirs • reservoirs receive water by gravity flow or pumping • Capacity of approximately 220 million gallons • Security surveillance cameras monitor the reservoirs 24 hours per day • Open reservoirs must be cleaned every six months • All 3 reservoirs store 3 days’ worth of water
Testing Portland Water • Performs 54, 400 analyses on 11, 800 water samples each year • Samplers collect water from the watershed reservoirs, in-town reservoirs, the distribution system , groundwater and consumers' taps
Treating Portland Water • Currently not filtered • Meets the filtration avoidance criteria of the 1989 Surface Water Treatment Rule • Waiver from the requirement to filter since 1991 • Bull Run water is very soft: typically ranges from 1/3 to ½ a grain of hardness per gallon • Portland's groundwater hardness is approximately 5 grains per gallon -- considered moderately hard • No fluoride added
Disinfection • Portland's water: chloramination 1. chlorine to disinfect the water 2. ammonia to ensure that disinfection remains • New federal regulations may require additional treatment processes by 2013
p. H adjustment for corrosion control • January 1997: Portland Water Bureau began corrosion control treatment – raise p. H of the water so less likely to leach metals – target p. H range is 7. 8 to 8. 0 • at least a 50 percent reduction in lead at the tap with p. H adjustment
Safe Drinking Water Act (SDWA) 1974 • Set the standard for public drinking water nationally • In 1986 Act amended: increase requirements for safety testing • In 1996 Act amended: increase source protection, capacity to carry water to the public
How water gets to the sink • to Portland by gravity • Through water mains to all parts of the city -- run beneath sidewalks and streets to individual homes and businesses • a smaller pipe travels to the water meter at each home or business not on a well – water passes through the meter on its way to your home to measure the amount of water your house uses – mains and the water meter owned by the City of Portland • ater enters pipes which are the owned by property owner. Those pipes deliver water to your tap.
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