Sinkhole Danger from Abandoned Septic Tanks and Cess Pools
Millions of homes, 60 million by one estimate, in the United States have a danger in their yards that they don't even recognize. That danger is old septic tanks and cess pools, abandoned when sewer service became available. The ground over these empty tanks can collapse without warning, and whatever or whomever is standing or playing there at the time can disappear in a moment.
This can happen in neighborhoods all across the U.S. In Allentown, N.J., James Carter was playing in his backyard when the ground under him suddenly opened up. The 2-year-old fell into an abandoned septic tank. His mother witnessed the event and was able to grab his outstretched hand and pull him to safety, as dirt and stones continued to fall onto his face. Weeks later, a second cesspool collapsed in the same yard, but fortunately no one was hurt.
Other families have not been so fortunate. In Stratford, N.J., a woman plunged 15 feet into a cesspool behind her house and died. That same week, in Ingleside, Texas, Maria Carmen Gomez was killed when she fill into an abandoned tank close to her front door. She was only two years old.
The danger is most pronounced in suburban neighborhoods built before the 1970s. At the time many of those areas did not have central sewer service so they installed septic systems. As the cities grew outward they brought in sewer lines and the septic tanks were abandoned in place. Age has worked its woes on the concrete or fiberglass of the tanks, and now they are beginning to fail unpredictably.
How can you tell if your house has this kind of hidden danger? Your local zoning office can tell you if your neighborhood had central sewers when the house was built. If not, then the chances are great that there is one or more septic tanks lurking under the yard. A septic contractor can survey the yard to locate any tanks, and a contractor can fill any found with solid materials like sand, gravel or concrete so they will not collapse. The cost of this procedure varies with size and location of the tank, but is likely to be between $500 and $2000.
For your own safety and peace of mind, you owe it to yourself to discover and fill these lurking hazards.