What is it about septic systems? They are forgotten until there is trouble, and then they can be a nuisance. What do they do and how do they work? How can we ward off septic trouble before it happens?
Septic systems are a part of Vineyard living for most residents, and like a good TV series they do not last forever. Houses within the areas supported by the waste disposal systems of Vineyard Haven, Oak Bluffs, and Edgartown are spared the need of a septic system, but outside those areas septic systems are the rule, and knowing how to care for and maintain them can lengthen their life.
Certified septic inspector Doug Cooper recently shared some of his knowledge and experience with septic systems. An environmental consultant who calls himself “a septic guru, a septic counselor,” he has been the principal in Cooper Environmental Services since 1995.
Mr. Cooper has 35 years of experience in natural resource protection and management. With a BA in geology and a master’s degree in agronomy (the science of soil management and crop production) from the University of Connecticut, he has a notable background in wetlands, hydrology, soils, and subsurface sewage disposal. His master’s thesis is entitled “Longevity of Subsurface Sewage Disposal Systems.”
Septic systems are simple, cost effective, and efficient ways of getting rid of household wastewater in areas where there are no sewers available, according to Mr. Cooper. He said that the typical septic system we see today is actually made with 1930s technology. Before that time household waste often went into single-tank cesspools, a hole in the ground with walls made of stone, blocks, and or bricks. Some older houses on the Island still have cesspools.
The U.S. public health service first suggested in 1935 that putting a septic tank in front of a leaching facility of some sort would enhance the treatment by capturing solids and letting them break down by bacteriological action — like a liquid compost, Mr. Cooper said. Septic systems of this type have become the rule nationwide in the decades since.
The clarified water that leaves the septic tank goes into a leaching system, a pit or field and that introduces the wastewater into the soil, the final part of the system. Soil contains bacteria that further break down waste material, and the soil acts as a filter.
Many homes on the Vineyard have a leach pit, which was the primary form of leaching system on the Vineyard for many years. Leach pits are large concrete cylinders perforated with holes that are buried surrounded with a layer of gravel.
A leach field is usually a system of perforated pipes, buried at a shallow depth, radiating out from a distribution box surrounded by gravel or crushed stone that spreads the effluent over a much wider area than leach pits. The field approach creates a much more efficient and longer lasting system, according to Mr. Cooper.
Current state regulations, known as “Title 5″ or “Title V,” have almost eliminated the use of leach pits. Mr. Cooper said that the law regulating septic systems has always been “Title V,” even though the term is widely used to designate the latest set of regulations.
Most systems are somewhat self-sustaining, Mr. Cooper said. “The waste that comes from the average household adds the necessary components to keep it working.”
Solids left to settle in the septic tank should be pumped out from time to time. The frequency of the pumping is a function of how much the system is used, according to Mr. Cooper. He pointed out that the state recommends pumping every five years. But he said that is too often for many households.
Seasonal houses generally won’t need to be pumped out as often as houses that are lived in year-round, and houses with more occupants will need more care than those with fewer people. He said that the average home of four should have its tank inspected every five years, but that most homes will not need to be pumped that often. He said that overly frequent pumping may disrupt a functioning system by removing the active parts of the process.
The Town of Tisbury is the only Island town that requires a septic inspection, every seven years, after the initial inspection. New construction and houses being sold must have their septic systems inspected in all Island towns.
Mr. Cooper said that in addition to having a system inspected at reasonable intervals, the best way to extend the life of a septic system is by using water conservatively. He says that garbage disposals, which usually add too many solids, are not compatible with septic systems, and he advises a judicious use of soaps and detergents which can kill off the bacteria that is the life of a septic system.
There are several practices almost guaranteed to destroy a working system, according to Mr. Cooper. Putting grease down the drain can be a septic killer. He said that washing latex paint down the drain or drywall plaster which painters and contractors often do when cleaning up, can be extremely harmful. These substances tend to clog the leaching capacity of a system, and there is almost nothing that can be done to unclog it.
Once the soil around the system has become clogged, Mr. Cooper said, there are few options other than installing a new system which can cost as little as $6,000 or $7,000 or as much as $30,000 or more, depending on the type of system the locale requires.
Counseling septic users is one of the services Mr. Cooper offers. He said that he has encountered “septic worriers,” people who suffer from “septic paranoia,” so concerned about their systems that they will not use bleach with their laundry for fear of killing the bacteria that septic systems need.
Don’t worry, he says. “You cannot use enough chlorine to kill a system.” The systems are so large, relative to the amounts of bleach and most other household cleaners, that they are not a problem.
“You cannot measurably harm a system with the casual use of normal household bleach and cleaners.”
Septic inspectors certified by the State charge from $150 to $325 per inspection. Some have additional hourly charges to locate the system.
Pumping and hauling charges begin at around $.60 per gallon, (the Edgartown waste-water treatment plant charges the haulers $.28 per gallon) plus the pumping permit fees which vary from town to town, from $10 to $40 depending on a number of variables. Most residential systems have either 1,000- or 1,500-gallon septic tanks. Sometimes if leach pits are pumped out as well another 1,000 gallons can be added to the bill. Pump-out costs range from $600 to twice that.