Portlands Drinking Water

Portlands Drinking WaterSafe Drinking Water Act (SDWA) 1974EPA 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 publicBull Run--Source

102 square-mile areaprimary drinking water supply for PortlandLocated 26 miles from downtown Portland in Sandy River basin, in Mt. Hood National Forest Portland Drinking WaterProtected in 1892Serves 900,000 residents 2001: protection boundary extended by federal lawGroundwater back-up supply since 1986peak water demand during summer monthsemergency source of supply when Bull Run is not available

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ReservoirsUncoveredReceive water by gravity flow or pumping17 billion gallons storedStore 3 days worth of water

Powell Butte ReservoirPurchased in 1925 for $135,000 for future reservoirs1981 the first reservoir operationalCurrently being expandedcompletion expected 2014Replacing volume of Mt Tabor/Washington ParkSecurity surveillance cameras monitor the reservoirs 24 hours per dayOpen reservoirs must be cleaned every six monthsWill be disconnected in 2015Mt. Tabor & Washington ParkTesting Portland WaterPerforms 54,400 analyses on 11,800 water samples each yearSamplers collect water from the watershed reservoirs, in-town reservoirs, the distribution system , groundwater and consumers' tapsTreating Portland WaterCurrently not filteredMeets the filtration avoidance criteria of the 1989 Surface Water Treatment Rule Waiver from the requirement to filter since 1991Bull Run water is very soft: typically ranges from 1/3 to a grain of hardness per gallonPortland's groundwater hardness is approximately 5 grains per gallon -- considered moderately hardNo fluoride added

Disinfection2012: received variance for cyrptosporidiumPortland's water: chloraminationchlorine to disinfect the waterammonia to ensure that disinfection remains

pH adjustment for corrosion controlJanuary 1997: Portland Water Bureau began corrosion control treatmentraise pH of the water so less likely to leach metalstarget pH rangeis 7.8 to 8.0at least a 50 percent reduction in lead at the tap with pH adjustmentsoft water

How water gets to the sinkTo Portland by gravityThrough water mains to all parts of the city --run beneath sidewalks and streets to individual homes and businessesSmaller pipe travels to the water meter at eachhome or businessnot on a wellwaterpasses through the meteron its way to your hometo measure the amount of water your house usesmains and the water meter owned by the City of PortlandEnters pipes which are the owned by property owner. Those pipes deliver water to your tap.3/7Demo: testing drinking waterEarth Resources Discussion Thursday: Joe, Abby, Daniel, BaisleyEarth Resources Discussion Friday: Francesca, Eli, Dreyson, KyleFriday 3/8 last day for discussions, assignment list grading, log 1

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