Homeowners are sometimes tempted to buy cheap, low-quality septic tanks because the process of installing a septic system is, admittedly, quite pricey. But recent research shows bad septic tanks—or even quality tanks that are just the wrong fit for the environment—can backfire spectacularly. They’re rarely worth it in the long run.
Septic systems are much more complicated than a simple tank or hole in the ground that you can run a pipe to. And bad septic tanks—namely, old and cheap ones—can be blamed for a host of wastewater treatment problems.
To filter and dispose of wastewater in a way that is healthy and sustainable for local watersheds, septic systems have to account for soil depth, groundwater locations, local microbial activity, climate conditions, and the availability of space around the tank. If a septic system is not properly designed for its environment, the risk of sewage contamination is much higher. This isn’t just a threat to local water supplies; untreated wastewater can also harm local watersheds and habitats while costing owners a fortune to pump or replace outdated septic tanks.
Millions of Americans rely on septic systems to treat their wastewater. According to one survey by Michigan State University, 30 percent of homes in the U.S. have septic tanks—a figure that’s much higher in states like Massachusetts, Florida, New Jersey, and New York. They are especially important in rural communities without access to municipal sewage networks. The problem is many of those systems are old, outdated, or in violation of local sanitation codes.
A 2017 study published in Environmental Science & Technology blamed bad septic tanks for releasing pharmaceuticals, consumer chemicals, and other pollutants into the environment. To make matters worse, the study found wastewater treatment plants, which municipalities rely on to clean sewage, showed similar levels of contamination.
All this contributes to the state of the country’s overall wastewater infrastructure, which in 2017 received a D+ rating from the American Society of Civil Engineering. That report also cited poorly designed or outdated treatment systems for failing to meet environmental and sanitation standards.
In addition to toxic chemicals and pharmaceutical compounds, wastewater hosts pathogens that can sicken people. If not eliminated through soil filtration, these contaminants can rise to the surface or find their way back into local water supplies. Once infected, people can suffer diarrhea, fatigue, viral meningitis, and other illnesses. What’s worse, a failing septic system doesn’t warn you ahead of time: One day it will simply back up into your plumbing or saturate your yard with toxic sewage—and it can cost tens of thousands of dollars to fix.
So what’s the deal? What exactly is wrong with America’s septic tanks? Why are they so bad, and what can be done to fix them?
To understand the problem, it’s important to know a bit about how septic systems work, and what kinds of septic designs are available to most people.
There are many different kinds of septic systems, but they all share a basic function—which is to contain, filter, and eventually purify your home’s wastewater. Once cleansed of harmful pathogens and contaminants, the wastewater is safe to re-enter the groundwater system around your home, where it will eventually make its way back into local water supplies and habitats.
Most septic systems work by storing wastewater in a collection chamber drained from your home’s sewage line. Bacteria inside the tank work to break down the wastewater, separating the refuse into three layers: scum, sludge, and effluent. The scum is a layer of oil and grease that rises to the surface of the wastewater. The sludge is solid or organic matter that sinks to the bottom of the tank; it is not biodegradable and must be periodically pumped out (ideally every 1-3 years). That leaves the effluent, which is the bulk of the wastewater itself; as a liquid it is discharged through piping to surrounding ground soil. This is called the “drain field” or “absorption field.” Once in the soil the wastewater is naturally filtered and cleansed of harmful pathogens, and eventually it makes its way back into the local water network.
At least, that’s how it should work…
Bad septic tanks—those that cause problems for local habitats or sewage systems—can be attributed to a number of things. Most of the time, though, a system fails because the drain field is over saturated or has admitted too much solid organic matter. Sometimes systems fail because the owner flushes oils or hard matter that, over time, clog the drain field and pollute the surrounding soil. Sometimes the tank is simply overtaxed—it’s not big enough for the amount of wastewater flushed out by residents. Other times homeowners just install the wrong type of septic system because they want whatever’s cheapest. Sloped properties with shallow soil depths demand more expensive, sophisticated drip disposal systems with aerobic treatment chambers; installing a conventional system on such a property will likely cause untreated sewage to permeate the drain field.
Now let’s look at the different types of septic systems. There are five basic designs, each with its own set of concerns regarding the environment of the home:
Conventional/gravity septic systems are the cheapest and easiest to maintain, but they are also the most problematic. Without any pumping or pressure system to advance wastewater, they rely on gravity or naturally occurring slopes to move water from the tank to the drain field. Many local governments have strict regulations or outright bans on their use because they’re more prone to failure in the event of earth shifts or faulty installation. They usually cost around $4,000-5,000.
Conventional pump systems cost only a little more and ensure better distribution of wastewater throughout the drain field. They also allow the drain field to be constructed uphill from the tank or from your home.
Pressure distribution systems are used when the property is steeply sloped or the soil depth is too shallow.
A pressure manifold system is similar to a basic pump system, but it allows for more advanced control of the flow and distribution of wastewater throughout the drain field. These, too, can be be built up slope from a tank or home, and they usually cost around $6,000-8,000.
Low pressure pipe systems are used for steeper slopes and lower soil depths and typically run anywhere from $12,000 to 15,000.
Drip disposal systems lower the risk of soil overflow and contamination by slowly “dripping” small amounts of wastewater throughout the drain field. These are ideal in areas where trenches are difficult to build and only a shallow region of soil is available for drainage. But they’re a lot more expensive.
There are two types of drip disposal systems: aerobic and anaerobic. Aerobic systems work somewhat like municipal sewage treatment plants by injecting oxygen into the tank, thereby accelerating the bacterial activity that breaks down waste. These typically sell for $25,000-40,000. Anaerobic systems employ the same drip disposal design but without the aerobic enhancement. They typically cost anywhere from $17,000 to $25,000.
And then there’s the material the tank is made from…
Septic systems account for the entire waste disposal and treatment for a property. But the tank itself also comes with a number of concerns that buyers should pay attention to—not least of which is the material it’s made from.
Most septic tanks are made from either plastic or concrete. Older systems relied on concrete because it was sturdy, widely available, and long-lasting. Concrete can withstand the rigors of construction, weather, and ground shift. The problem is that concrete is porous and prone to cracks, especially as it ages. If it’s reinforced with steel rebar it runs the risk of rusting, which could eventually contaminate the drain field. Concrete is also extremely heavy and, therefore, pretty expensive to transport and install. Once its lifespan is up, that also means it will be expensive toe remove and replace.
Plastic, on the other hand, is a much lighter material—no need to hire heavy machinery to lift or lower the tank into place. This also makes plastic tanks easier to transport, which is ideal for more remote homes where transportation costs can rack up quickly. Finally, there’s no risk of corrosion or rusting with plastic septic tanks. In all, plastic septic tanks are much cheaper to purchase and install.
Of course, there are some downsides to plastic. In areas with high water tables, plastic tanks are at risk of “floating,” causing them to shift in the ground. This can strain piping systems, de-level the tank, or cause leakages. While durable, polyethylene plastic is also no match for concrete, so extreme conditions may still pose a risk to the structural integrity of the tank.
There is no catch-all septic solution for every home. In most cases, the problem with bad septic tanks is not the tank itself—it’s that it was the wrong tank for the job. Owners really need to account for environmental factors in deciding which kind of system tank is best for them: What are the soil conditions? How much soil depth is there for the drain field? Will the drain field need to be installed uphill from the tank? What is the slope of the property? What kind of vegetation surrounds the property? How many people live on the property? How much wastewater does the homeowner expect to produce? What is the local climate? How will heat and humidity accelerate or impede the breakdown of wastewater? Will effective treatment require aerobic assistance? What are the local environmental regulations?
Before even thinking about which type of system you need you should hire a professional to perform a soil analysis. This will give you a good idea of what environmental factors you need to consider when choosing a septic tank. While the process may seem daunting, doing your research and taking time to factor in as many variables as possible will get you most of the way there. And if ever you feel overwhelmed, the experts at GoToTanks are here to answer any questions you may have.
SALES@GOTOTANKS.COM 
