Portlands Drinking Water Safe Drinking Water Act SDWA

Portland’s Drinking Water

Safe Drinking Water Act (SDWA) 1974 • EPA standard for public drinking water • 1986: Act amended to increase requirements for safety testing • 1996: Act amended to increase source protection, capacity to carry water to the public

Bull Run--Source • 102 square-mile area • primary drinking water supply for Portland • Located 26 miles from downtown Portland in Sandy River basin, in Mt. Hood National Forest

Portland Drinking Water • Protected in 1892 • Serves 900, 000 residents • 2001: protection boundary extended by federal law • Groundwater back-up supply since 1986 – peak water demand during summer months – emergency source of supply when Bull Run is not available

• • Reservoirs Uncovered Receive water by gravity flow or pumping 17 billion gallons stored Store 3 days’ worth of water

Powell Butte Reservoir Mt. Tabor & Washington Park • Purchased in 1925 for • Security surveillance $135, 000 for future cameras monitor the reservoirs 24 hours • 1981 the first reservoir per day operational • Open reservoirs must • Currently being be cleaned every six expanded— months completion expected 2014 • Will be disconnected • Replacing volume of in 2015 Mt Tabor/Washington Park

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 • 2012: received variance for cyrptosporidium • Portland's water: chloramination 1. chlorine to disinfect the water 2. ammonia to ensure that disinfection remains

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 • “soft” water

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 • 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 • Enters pipes which are the owned by property owner. Those pipes deliver water to your tap.

3/7 • Demo: testing drinking water • Earth Resources Discussion Thursday: Joe, Abby, Daniel, Baisley • Earth Resources Discussion Friday: Francesca, Eli, Dreyson, Kyle • Friday 3/8 last day for discussions, assignment list grading, log 1