Written by Stephen R. Henshaw, P.G., President & CEO, EnviroForensics
As seen in the March 2013 issue of Cleaner & Launderer
You can imagine that if wastewater is discharged into a sewer line with cracks in it that the wastewater could contaminate the soil and groundwater. After all, sewer pipes can be very old and made of a variety of material such as transite, clay, concrete, plastic, or steel. Of course, leaks are not uncommon in sewer lines. Sewer lines can crack or break, they can corrode, or the couplings, where pipes are fitted together, can leak and result in “point source” areas of contamination. Sags and low points are common when a sewer line goes underneath streets and structures. These low areas can result in sediment and dense chemical liquids pooling in these sag points, resulting in contamination source areas. Sewer pipes can become blocked and clogged and result in backups that can create points of leakage.
Historically speaking, sewer pipes were not designed to be leak proof. The first sewers were essentially brick lined tunnels. Later, short sections of clay pipes were coupled together to create long lengths of sewer. The clay sections consisted of a male end and a female (bell) end and the lengths of clay pipe were coupled together. Gaskets were hopefully placed in the bell end to minimize the leakage, but of course those gaskets would degrade over time. Transite pipes and concrete pipes similarly had male and female ends and were coupled together. Continue reading “PREFERENTIAL PATHWAYS; UNDERGROUND PIPES AND UTILITY LINES CAN BE CONDUITS FOR THE MIGRATION OF CONTAMINANTS”