SEPTIC SYSTEMS AND THEIR EFFECT ON THE ENVIRONMENT
By Jessica Lemieux
Septic systems are wastewater systems that treat sewage on-site and release the treated effluent back into the ground. A septic tank is a key component of a septic system. It is a small-scale sewage treatment system that is common in areas that don’t have a connection to main sewage pipes.
When a septic system fails, contaminants such as nitrogen and phosphorus, enter the environment, which can have negative effects, including contributing to the eutrophication of the Great Lakes. Phosphorus, specifically, is a known cause of the blue-green algae (cyanobacteria), present in an increasing amount of lakes.
In the various studies conducted on the effects of failing septic systems to the environment, there have been differing opinions and conclusions drawn.
In a report from Michigan State University, Joan Rose gives her conclusions for her 2015 study, Linking fecal bacteria in rivers to landscape, geochemical, and hydrologic factors and sources at the basin scale. Joan Rose is the Chair in water research at Michigan State University and is also the 2016 recipient of the Stockholm Water Prize.
The 2015 study tackles the evaluation of water quality, potential health implications and the impact of septic systems on watersheds.
“All along, we have presumed that on-site wastewater disposal systems, such as septic tanks, were working. But in this study, sample after sample, bacterial concentrations were highest where there were higher numbers of septic systems in the watershed area.”
“For years we have been seeing the effects of fecal pollution, but we haven’t known where it is coming from. Pollution sources scattered in an area - called non-point [sources] - have historically been a significant challenge in managing water quality.”
She explained that discharge-to-soil methods are not able to filter human sewage and do not keep E. coli (Escherichia Coli) and other pathogens from water supplies.
Rick Esselment, President & Founder of ESSE & Associates Inc. and former President of the Ontario Onsite Wastewater Association, offered his expertise on the subject.
“A conventional septic tank system does leach into the soil on the property, and then percolates down to the soil so it reaches the performance boundary. At that point, with the current building code on how these systems are installed and designed, the water would be safe to enter into the groundwater table. If the systems are designed, installed and maintained as per the current Ontario building code, they are actually safe for the environment, which is an important feature. Conventional or standard septic systems, on their face, are actually a very green piece of infrastructure. Septic systems work really well for a very long time.”
According to Environment and Climate Change Canada (ECCC), Septic tanks are a widespread and dangerous point source - meaning a single identifiable source - of groundwater contamination.
ECCC said, “Septic systems are designed so that some of the sewage is degraded in the tank and some is degraded and absorbed by the surrounding sand and subsoil. Contaminants that may enter groundwater from septic systems include bacteria, viruses, detergents, and household cleaners. These can create serious contamination problems. Despite the fact that septic tanks and cesspools are known sources of contaminants, they are poorly monitored and very little studied.”
Esselment argues that the issue isn’t with septic tanks, themselves, but instead with the lack of maintenance and knowledge of septic tank owners. He says the issues arise due to the failure to replace septic systems that have exceeded their lifetime.
“Septic systems work great. They work really well for a long time, but when they stop working, they really need to be replaced. That’s the contamination issue. When they’re not taken care of and they’re not replaced, they absolutely contaminate the environment. The lack of maintenance, caring and knowledge of septic tanks is what is contributing to contamination, not septic tanks themselves.”
“The approximate life expectancy on a septic system ’soil filter’ is 35-45 years, which is actually quite impressive and robust. So, the challenge comes in once they’ve passed their functional life expectancy.”
According to Health Consequences of Failing Septic Systems, a report from the Galveston County Health District in Texas, failing septic systems pose severe health hazards to communities.
What Diseases Are Commonly Caused by Wastewater?
Septic tank systems are the largest of all contributors of wastewater to the ground and are the most frequently reported sources of groundwater contamination in the United States. Bacteria, viruses, and parasites (including worms and protozoans) are the types of pathogens in wastewater that are hazardous to humans. Fungi that can cause skin, eye, and respiratory infections also grow in sewage and sewage sludge. These bacteria and viruses may be transported very rapidly and could contaminate nearby drinking water supplies or recreational surface water.
The types of parasites found in wastewater include protozoans and parasitic worms. When people drink water contaminated with protozoans, they can multiply inside the body and cause mild to severe diarrhea. Another protozoan is the cause of amebiosis, also known as amebic dysentery. Parasitic worms can also dwell in untreated sewage. Tapeworms and roundworms are the most common types found in the U.S. Their eggs are found in untreated wastewater and can be ingested.
Esselment continues to assert that the issue is not with septic systems and the technology, itself, by giving an example:
“If it was a car, for example, the car would stop running and you’d buy a new one, but because you can keep flushing a toilet, people keep using broken septic systems which further contaminate the environment.”
“The failure in Ontario is of governance and policy - it’s not a failure of existing governing bodies, as the regulators who are doing the work, are doing a great job with the tools they have. However, the tool they have right now is just a permit. So, if someone wants to install a new septic system, or upgrade a septic system, the applicant would come in with a permit and the building official would review the permit for its efficiency and its building codes. If it met the minimum standards and the building codes, they would issue a building permit and would do an inspection to make sure it was installed properly, but from that point forward, the homeowner is responsible. That’s it. That’s the only tool [the regulators] have available.”
“Recently, in the last five years, the province has endeavoured to advocate for municipal reinspection programs, meaning based on the risk assessment, the municipal building official would commission the inspection for the system to ensure that it was still functioning and being maintained. The program was intended to capture some of these failures. The challenge is the program is only being used to areas where there are municipal wellheads - so it’s really just protecting municipal drinking water.”
Wellheads are the topmost point of a well. They serve a number of functions while a well is being drilled and once it is completed and operational. The wellhead serves as a point of attachment for a blowout preventer, which is a piece of equipment that prevents the catastrophic failure of a well. Once a well is completed, equipment for regulating well operations can be attached at the wellhead.
“The mandatory inspections are only restricted to areas where there is a municipal wellhead within a certain distance. So, it falls flat to protect our recreational water and ground water that is being used by people who aren’t in the municipality. It leaves everyone else vulnerable, including all the other good people in Ontario who need to know that their neighbour is being held accountable. The failure is of a policy to make sure people take care of their responsibility.”
Esselment explained that a huge challenge with septic systems in Ontario is that there is no mechanism to capture when they’re failing.
“At the end of [a septic tank’s] lifetime of approximately 35-45 years, as there is no mechanism to capture that they’re failing, homeowners often don’t realize it until there is a catastrophic failure where there is sewage coming to the ground’s service. Once it reaches this point, it means that the septic tank may have already contaminated the lake or the groundwater table for a number of days, weeks, months or years.”
Esselment explained that while he was president of the Ontario Onsite Wastewater Association, a policy was put together to propose that mandatory maintenance reporting of all septic systems be required. This would mean that system owners were required to produce a report stating that their system is continuing to function. If they don’t report, the municipality could then give them an order to produce the report. By requiring mandatory maintenance reports from people with septic systems, municipalities would have the ability to audit those reports, which would capture a lot of the failures. This would be a solution to the current failure to recognize and deal with systems that are not working - or that have gone way past their life expectancy - which contributes to a substantial amount of contamination getting into the groundwater and recreational surface water.
Illustrative of Esselment’s assessment is the personal experience of a Québec cottage owner, Peter.
Peter said, “When I bought [the cottage] there was already a septic tank installed that was fully functioning and never gave us any issues. We didn’t think to have the tank inspected and were not clear of the exact process, or even that the responsibility [of the septic tank] fell on us, for that matter. We have always lived in the city where this was never something we had to deal with. We found out the hard way, though, when we had sewage [seeping out] everywhere. That was a terrible mess.”
“Our lake’s council has annual meetings now, too, as we had blue-green algae [blooms] a few years ago. Maintenance of septic tanks is now discussed with all cottage owners as well as the need to reduce the use of cleaning products and soaps that contain phosphorus.”
An interesting point of note is that, contrary to popular belief, eliminating soaps and detergents that contain phosphorus will not stop it from entering septic tanks, as there is phosphorus that enters water treatment facilities through broken down food.
Esselment explained, “When the [septic] system isn’t working properly, it releases untreated septic tank effluent into the environment. It’s the phosphorus in septic tank effluent that contributes to blue-green algae in Canada’s lakes. The phosphorus comes from the breakdown of food. Even if people have stopped using phosphates in soap, it will still enter wastewater treatment, as they are in the food. There is no phosphorus treatment in septic tanks, so if they leave the septic tank, they just pass right through as a dissolved nutrient and gets into an environment, which could contribute to blue-green algae.”
He believes that the federal government could assist by providing resources to the province for the municipal regulatory groups.
“The local building official just doesn’t have the administrative staff and resources to make sure that all these systems, that are their responsibility, are continuing to be adequately looked after. It is a policy resource problem. The provinces and municipalities just don’t have the resources, so the federal government could step up and help in that regard.”
“Policy support for people to do maintenance and check in at 3-5 year intervals, as well as the resources that allow that to happen, is all it takes. People would become aware when they got a letter from their municipalities saying they need to know that their septic tank is working properly. Replacing a septic system can lead to a $20,000 bill, which isn’t always easy for people to manage with their limited means. With these maintenance intervals, though, people would be aware beforehand and have time to plan as their septic tanks approach their lifetime expectancy.”
“It takes public knowledge to realize the impact of septic systems on the environment. People need to recognize it’s their personal responsibility to take care of the water resources that we all share. Old septic systems don’t work anymore. If we don’t force people to take action, we are knowingly allowing them to continue to contaminate the environment.”
“We need to convert people to a culture of management and responsibility, as opposed to building it and replacing it once it fails. The environment can’t sustain dealing with all these failed systems before someone steps up to tell people that they have to replace their tank. It’s about proactivity. All infrastructure faces the issue of proactivity, it’s just that this is the one that contributes to the changes in our lakes and in our environment.”