Why is my Septic System Alarming?

You hear a muffled buzzing sound and finally step outside and realize your septic system is alarming. Many modern and alternative septic systems have alarms to notify the homeowner of a potential problem. In some locations like Prince William County the system also alarms in the house. So, what does it mean if an alarm sounds and what should you do? First of all, don’t panic.

There are a series of straightforward steps to take.

• Silence the alarm so you can think and you do not annoy the neighbors. There is considerable variation in septic systems and alarms. There should be a toggle switch on the outside of the control box. Flick it to the off or silent position. Here in Prince William County, we also have an alarms in the basement. You will have to silence that one too.
• Determine what type of alarm it is. Typically, it is either a high-water alarm or if you have a blower for an ATU tank the blower may be out.
• If you have a blower, feel the casing of the blower motor to make sure that the blower is operating. You can also often hear the hum of the blower. If not, call a licensed and certified septic repair company (not a septic pump out company) to replace the blower. You have a day or two before the undertreated sewage starts flowing to your leach field and begins to damage it. Get it fixed before that happens.
• If it is not the blower, then the alarm was probably a high water level alarm in your septic tank or your secondary tank.

A high water alarm is caused by either too much water going into the tank or not enough going out. A high water alarm if not properly addressed will cause septic waste to ultimately back up into your house, though that may occur after your drainfield is fully damaged. A typical septic system has four main components: a pipe from the home, a septic tank (or two), a drainfield (alternative systems might have drip fields, sand mounds or peat tanks where a traditional drainfield is not possible or has failed), and the soil. Many systems also have pumps to move the liquids from the home to the septic tank or from the septic tank to the drainfield, and all systems have pipes connecting the tanks and drainfield. There are also Alternative systems that have additional components such as; float switches, pumps, and other electrical or mechanical components including additional treatment tanks and filters which can clog if not cleaned and replaced regularly (depending on what you flush down the toilet or pour down the drain). It is the alternative systems and systems with pumps that typically have alarms.

A high water alarm is caused by one of two things:

1. Too much water flowing into the septic tank or
2. Not enough water flowing out.

If too much water is flowing in you either have a plumbing leak or a running toilet. After several years, the flapper in the toilet tank should be replaced because it does not always seal properly. Check every toilet (and tank) as well as all sinks for dripping faucets. Usually, it takes something like an incompletely closed faucet or running toilet and many hours to cause a septic tank to over fill. According to the U.S. Environmental Protection Agency, one out of every 10 homes has a leak that is wasting at least 90 gallons of water per day, look carefully for leaks.

The high water alarm is not likely to be caused by excess sludge in the waste tank, but it can happen when the tank has not been pumped for years and you have a couple of days of high volume usage or doing a month’s worth of laundry in a single day. That is what typically causes the septic system to backup during holidays and parties. A broken septic tank lid or cracked tank can also allow rain and runoff to enter the septic tank and over fill the tank. If it has not rained recently, or you were not running the hoses or a sprinkler, then that is unlikely to be the cause of a high water alarm.

If the problem is not the water entering the tank, then there is a problem with water leaving the tank. This could be caused by pump failure, a blockage in the line to the drainfield which may include a clogged filter, or clog in the drainfield itself. You need a septic service company to determine what is causing the problem, though check your circuit breakers to make sure that any pumps have power and you could pull the filter in the white pipe between your tanks and clean it out.

The basic design of a septic tank will only work if the sludge is not too thick on the bottom and the grease and scum is not too thick on top, and if the flow to the tank is not excessive. If there is too much waste on the bottom of the tank or too much water flowing to the tank, there will not be enough time for the solids and liquids to settle out before the tank starts releasing water containing large amounts of fecal waste to the drain field. The fecal waste will over time clogs the drainfield. Also, if there is too much grease and scum floating on top, the scum will be released to the drainfield. A septic system is not a trash can. Don’t put dental floss, feminine hygiene products, condoms, diapers, cotton swabs, cigarette butts, coffee grounds, cat litter, paper towels, latex paint, pesticides, or other hazardous chemicals into your system they can end up clogging the filter and/or lines if carried from the tank.

In addition, the National Small Flows Clearinghouse has seen septic distribution pipes plugged with a “noxious fibrous mass” that was grease and cellulose from toilet paper that only occurred in homes with water softening systems. A clog in the distribution system will also cause a high water alarm as the septic water cannot be released or pumped to the drainfield. It is believed that the brine in the conventional septic tank interferes with the digestion of the cellulose fibers and can be carried over into the septic systems drain field. A study in Virginia involving two adjacent septic field dispersal systems in a shared mound have shown that the trenches that received the septic effluent with water softener brine discharges formed a thick, gelatinous slime layer that clogged the infiltrating surface, while the trenches receiving no salt water discharge remained open with a normal microbial clogging layer. Commercial septic tank additives may assist in the breakdown of fecal waste, but do not eliminate the need for periodic pumping and can be harmful to the system. Saving money by not pumping your septic tank could result in the need to replace your drainfield.

Septic tank wastewater after preliminary settling and in alternative septic systems undergoing secondary treatment flows to the drainfield, where it percolates into the soil, which provides final treatment by removing harmful bacteria, viruses, and nutrients. The waste cannot contain too much solid material or scum. High quantities of solids in the waste stream will overwhelm the drainfield. Initially, nitrogen and fecal bacteria will be released to the groundwater as the soil becomes saturated with solids and scum. Eventually the perforations in the pipes to the leach field through which wastewater flows become clogged and the waste backs through the system. If a high-water problem is left unaddressed, the septic system will eventually back up into your home. Before the septic backs up into your home the high-water alarm will sound, attend to it.

This is an update and reprint of an older article.