Wastewater and its Environmental and Health Impacts

Water is one of the most fundamental natural resources that sustain human and all other forms of life. According to the EPA and other organizations concerned with the health and environmental aspects of liquid waste, it is not even industrial water pollution but, rather, domestic wastewater disposal that is one of the most important environmental issues currently facing citizens in the United States. The fact is, nearly one in four households in the United States depends on some kind of septic system to treat wastewater from their household activities. In the U.S., septic tanks are reported as a source of ground water contamination more than any other source. Forty-six states cite septic systems as sources of groundwater pollution. Nine of these reported them to be the primary source of groundwater contamination in their state.

The Functioning of Septic Systems
All of the wastewater sewage that leaves a home, from its toilets, sinks, washing machines, etc enters the septic system through piping and flows into a huge holding tank. The septic tanks are designed so that the bio-solids in the sewage separate out from the liquid and fall and settle to the bottom of the tank. If the septic tank is working properly, it should be retaining all of the large bio-solids. Naturally occurring bacteria in the solids that do not need oxygen to thrive, called anaerobic bacteria, immediately begin to digest and break down the solid waste.
Once the solids have had time to settle out, the water is then treated and filtered. The “septic effluent,” or onsite wastewater, is then discharged through piping where it flows out into the ground next to the system into a “soil absorption system” called the leach field. The water discharged into the leach field interacts with the naturally occurring bacteria in the soil and this interaction causes a “biomat” to form. The biomat is a bacterial slime layer, composed of anaerobic microorganisms in the soil below, which digest as much of the biological solids and pathogen waste in the effluent as it can.
So, in effect, we are relying on the processes of nature to decontaminate the sewage that first enters the tank, settles to the bottom where bacteria begin breaking it down, as well as the remaining liquid waste discharged into the soil where it is digested and broken down by the biomat to acceptable levels of safety, after which the water moves into the remaining soils. The formation of the biomat is thus fundamentally necessary because inadequate treatment of effluent would mean that sewage and pathogens would be discharged into and contaminate nearby ground water.
However, if too much of the biomat forms, it tends to decrease the soil infiltration rate, which can effectively clog up the whole system by not allowing the water to take its natural course and run into the remaining soils. If that happens, the sewage wastewater builds up and once the amount of water exceeds the ability of the soils to naturally absorb the effluent, then untreated sewage water either backs up into the home or is forced into the surrounding soils, eventually causing contaminated wastewater to be introduced into the water table and bodies of water such as streams and lakes, polluting all of the water it comes into contact with.
The technical term for when the levels of effluent exceed the ability of the soils to receive it is called “hydraulic overloading.” According to experts, as many as 75 percent of all system failures are attributed to hydraulic overloading. Therefore, it is crucial for both owners of septic tank systems as well as professional inspectors, installers, and servicers of septic systems to have a solid understanding of hydraulic overloading and its possible causes.

The Possible Cause of Failures of On-site Septic Systems
Hydraulic overloading can be avoided with regular inspection, pumping and maintenance of the septic tank and system. Any lapses lead to hydraulic overloading. One of the reasons for these lapses is that your average homeowner has little knowledge about how their septic system works, never thinks of it, and is often even unaware of how old it is, or whether preemptive planning is necessary before the system fails. Some failures are due to inadequate inspections, improper siting, and inadequate installation of septic systems.

Possible Pollution and Contamination and of Onsite Wastewater
Contaminated wastewater overflow from clogged, backed-up, or even broken or leaking septic systems can be very dangerous and places the local drinking water and other sources of water use at risk. According to EPA studies of possible contaminants from malfunctioning septic systems, health and environmental risks include “disease-causing bacteria, viruses, protozoa, and intestinal parasites” as well as “dangerous organic compounds such as trichloroethylene, toluene, methylene chloride, benzene, chloroform, and other volatile synthetic organic compounds,” many of which are cancer-causing. The synthetic organic compounds come from home use of chemicals that are found in “pesticides, paint and coating products, toilet cleaners, drain cleaners, disinfectants, laundry solvents, antifreeze, rust proofers, septic tank and cesspool cleaners, and many other cleaning solutions.” According to the EPA, “between 820 and 1,460 billion gallons of this contaminated water are discharged per year to our shallowest aquifers.”

The Role of the Liquid Waste Industry
Given everything that has been said, everyone involved in the liquid waste industry has their roles to play to ensure that citizens always have clean and healthy water available. It is really each state and each community that regulates water, following of course national governmental laws such as the Clean Water Act and the advice of the EPA and other agencies. One of the reasons it is up to each state to regulate, produce laws, and enforce them is due to fact that land formations and local ecologies can be radically different from one another.
The land in and around San Antonio, Texas, for example, is so rocky, that the rules, laws, regulations, and enforcement are tied to the unique aspects of the land formation of that area. “Because of the excessively rocky soil in and around San Antonio, ninety-nine percent of all septic system installations in our area are ‘aerobic’ systems’ says Courtney Van Delden of Van Delden Wastewater Systems, a company that installs, services, and inspects septic tank systems in the San Antonio area. “This is compared to your ‘typical’ system that relies on anaerobic bacteria to function properly” says Courtney.
“The main difference between ‘anaerobic’ and ‘aerobic’ septic tank systems is basically the presence or absence of oxygen in the system” says Karl Holt owner and president of Aero-Stream, a company located in Harford, Wisconsin. Holt is the inventor of a kind of aerobic septic tank system. Anaerobic systems rely on bacteria that thrive in an oxygen free environment. As discussed above, anaerobic bacteria are naturally occurring in bio-matter and so typical septic systems rely on the these kind of bacteria to both breakdown the bio-solids at the bottom of a septic tank as well as the formation of the biomat that breaks down the rest of the bio-solids in septic tank sewage water before the water enters the soils beyond the leach field.
In contradistinction, an “aerobic” septic tank system relies on bacteria that thrive in an oxygen rich environment. For the system to work properly, oxygen needs to be introduced into the system which converts the anaerobic bacteria to aerobic bacteria, and Holt’s system is designed to do just that. “Through research and development I patented an easily installed process that converts the anaerobic system to an aerobic or oxygen rich system,” Holt tells us, continuing “by introducing oxygen into the septic tank, aerobic bacteria thrive and consume 20-30 times more organic material than anaerobic bacteria.” According to Holt, “what makes aerobic systems so different from anaerobic systems is that the aerobic bacteria digest more of the bio-solids in the septic tank and that dramatically reduces the amount of nutrients in the septic tank effluent that the biomat requires to live and grow.” What is more, “the biomat is further reduced in size by aerobic bacteria that leave the septic tank that further reduce the ability of the biomat to live and grow,” says Holt. If the biomat has less of a chance to grow to the point where it blocks the system, then less biomat means less of a chance of hydraulic overloading.
However, while it is true those aerobic bacterial colonies are better at breaking down bio-material like human wastes than anaerobic bacteria, according to the U.S. Department of Agriculture, “aerobic bacteria are less susceptible to household chemicals than anaerobic bacteria.” Aerobic systems have their drawbacks, especially if homeowners get rid of lots of chemical products down the drains and toilets in their homes. According to Courtney Van Delden, “since the aerobic bacteria are less able to break down inorganic solids, they system can be clogged more easily. Plus, because these kinds of systems require constant aeration, they need a steady and reliable source of electricity to run the machines that introduce the oxygen into the system.” Van Delden says that “because there are more working components like the electrical system, and due to the rocky soil conditions in our area, septic tanks are required to be checked and pumped every four months in most of the counties in and around San Antonio.” This is compared to the general recommendation that anaerobic systems be pumped at least once a year.

Andrew Coleman, of Skip’s Wastewater Services, from Tolland, Connecticut discovered a new way to dispose of the waste that his septic pumper trucks collect. The method is eco-friendly because less waste is introduced into typical municipally run waste receiving stations referred to as Publically Owned Treatment Works (POTW). Coleman tells us that “in 2014 we decided to search for alternative options for where to discharge our septage. The local receiving facility charged a lot of money for the 7 million gallons per year that we discharged year after year. Plus, fuel costs were high driving all the way there. We hired an environmental engineer who specializes in wastewater. Along with an environmental attorney, we were able to develop our own receiving facility in an adjacent town.” Explaining this facility Coleman tells us that “the equipment consists of a JWC Honey Monster Septage Receiving System. The unit consists of a rock trap, a Muffin Monster dual shafted grinder, an actuated plug valve, and a magnetic flow meter. Septage is offloaded and flows through the unit, allowing the organic waste and water to flow to the sewer system while all inorganic materials (rags, rocks, grit, bolts, bathroom products, etc) get screened and removed. The process is highly effective. The trucks typically offload within a half hour, and are doing less traveling due to the location of our facility.” Because more of the solids in the septage are filtered out, they are not just emptied into the local water treatment plant. They can be disposed of more effectively once filtered. This is one of the benefits of using the Honey Monster Septage Receiving System that Coleman had the manufacturer of the system build and install in a nearby town. Coleman had some real pushback from the local POTW, however. As he explains “we are currently facing problems because the receiving treatment facility we used to use is working very hard to stop our operation. Being that they are a publicly owned treatment facility, they want to have a monopoly on the septage in the area, as it is a huge revenue stream for them. We have developed a very strong case to show that our screening facility is more environmentally friendly and more efficient than screening at the local POTW. To date we have discharged around 5 million gallons of septage through our facility and it has worked flawlessly.” POTWs are the typical kind of water treatment plant that most wastewater treatment companies use. Coleman found a cheaper and more environmentally-friendly solution.

Story by Mark Joseph Manion


No comments yet... Be the first to leave a reply!