Allegheny County Sanitary Authority
(map of service area) In Pittsburgh's early history, the Allegheny and Monongahela rivers were used as both drinking water sources and as sewers.
[2] As the city's population grew, its early haphazard collection of cesspools and privy vaults (outhouses) was replaced with a municipal combined sewer system that routed sewage into the area's tributaries and rivers, starting around 1880.
Although the Pennsylvania Pure Waters Act of 1905 banned the discharge of untreated sewage by any new municipal system, that practice continued in Pittsburgh.
[2] Since 2004, Alcosan has held an annual open house, typically the third Saturday in September, to educate the public and inform them about the likely changes in coming years.
In 2009, Alcosan paid $73,000 to Buchanan, Ingersoll & Rooney and $48,000 to Eckert, Seamans, Cherin & Mellott to lobby the Pennsylvania General Assembly.
Other portions of the area use more primitive combined sewers, where sewage and storm water are mixed and flow through the same pipe to Alcosan's plant.
[6] As of 2009, there are about 70 days a year when contact with river water in the Pittsburgh area is not recommended due to combined or sanitary sewer overflows.
In a 2005 study, a Carnegie Mellon University project tested water quality and found that only 32 percent of Allegheny County's streams meet Pennsylvania's safety standard for fecal coliform bacteria.
These precautions are particularly aimed at people who have open cuts or sores, and those with weakened immune systems who are most vulnerable to infection from exposure to contaminated river water.
That season typically lasts from May 15 through September 30 when the likelihood of exposure to river contamination due to sewer overflows and storm water runoff increases.
Local marinas and other sites along the river fly orange-colored CSO (Combined Sewer Overflow) alert flags indicating when an advisory is in effect.
[12] In addition to the CSO flag program, ALCOSAN maintains the online Sewer Overflow Advisory Key (SOAK) that "grades" current water quality by a visual color key, indicating conditions in terms of appropriate recreational uses and stores a history of water quality alerts online.
[17] This document described a Selected Plan which meets and exceeds these requirements, at a cost of $3.6 billion total in 2010 dollars (it would eliminate SSOs and capture 96% of CSOs), and entails the construction of 25 miles of new tunnel.
[16] Consequently, Alcosan proposed a Recommended Plan that is affordable, with a total cost of $2 billion in 2010 dollars, but that falls short of the EPA consent decree requirements, as it reduces SSOs by only 90% and CSOs by only 79%.
[18] While environmentalists criticized the plan because of components that include 15' diameter pipes to help handle peak storm water load, Alcosan in early 2017 announced a generous grant program to help municipalities employ green techniques, stream removal and other means.
