How Pittsburgh Combination Sewers Cause Water Damage

By Leo Francis

Unlike numerous houses in the suburban Pittsburgh area, the city proper and many of the older surrounding towns still have their storm water joined to their sanitary sewer inside the boundaries of the home. This obsolete system not just causes environmental problems for the community but can result in substantial water damage for the property owner. To understand why, we have to examine the history of the water and sewer system in Pittsburgh.

At the turn of the century as Pittsburgh began to grow as an commercial and industrial city, the typical means of human waste disposal was the privy or outhouse. Throughout this period Pittsburgh had the greatest number of Typhoid cases in the nation. This was credited mostly to contaminated drinking water, brought about by wells being situated too close to outhouses, and raw sewage being discharged into the water ways which also was a source for drinking water.

While the city matured it continued to create additional sewers, which in turn transferred both waste water and storm water through the same pipes and directly into the river. The thought simply being the rain water would aid flushing the raw sewage through the system. This uncontrolled disposal of raw sewage into Pittsburgh’s rivers did not stop until 1958 when the Allegheny Sanitary Authority opened up it’s sewage treatment plant. Sadly, to this day the treatment facility is unable to take care of all the storm and sewage pouring in into the plant on rainy days, inducing them to release overflows of waste water straight into the rivers.

The combination sewer turns into a problem for the individual homeowner whenever the home’s building sewer, leading to the main municipal line, gets blocked. Being that all the home’s exterior rain conductors are joined to the building sewer in the basement means none of the rain water coming down off the roof can get through to the municipal line. This causes the water to be forced up in the lowest spot, which is usually the basement floor drains. The water will continue to rise so long as the rain continues and the sewer is blocked. More than a foot of water can accumulate in the basement, leading to substantial water damage.

To prevent this costly scenario the rain conductors ought to be removed from the system. This may be mandatory for City of Pittsburgh residents in the near future, as it has been for suburban inhabitants for years. Till this is done it may be most effective to have your sewer professionally cleaned once a year, especially if you have encountered troubles with sewer blockages in the past.

Visit for more information on what to do, and who to call if you suffer water damage.

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