June 2013 – While Everyone Else Is Sleeping

How I Unwillingly Became Educated on my Septic System

Those of you who have read some of my previous This Old House posts may recall that our new house is on a septic system. That is because previous to Austin becoming this hip happening place that over 150 people move to per day, our part of town was considered out in the boonies. I still pass by horses grazing in the pasture on my way home every day so this may not be exactly past tense.

The septic system scared us a little during the 10 day option period. After all, the useful life of a septic system is typically quoted as 25 years and the house was already at year 21 when we purchased it. But we felt reassured by the fact that my parents, grandparents and sister and brother-in-law all live on septic systems much, much older than that. In fact the only impact a septic system had on me growing up was a lack of dishwasher and garbage disposal, recycled bathwater for the kiddos and filling the sink to wash dishes rather than letting the tap run. Easy peasy. And the one time green sludge backed up into the yard, my Dad jumped on his tractor and added more lines to the leach field himself.

Our System

We have a low dosed pressure system, which consists of two trash tanks (a main tank and a second considered a two day reserve tank), a pump tank with a pump and high water alarm and a disposal field. In our case, we have two fields, which we alternate between every 30 days. The waste water gravity feeds from the house to the main trash tank where the solids (aka poop) are deposited. The water then flows to the pump tank and once the water rises above the gray float, it is pumped to the leach field, where it eventually evaporates or percolates towards the surface. I think that is why they say the grass is always greener over the leach field. The high water alarm goes off when the pump tank gets over full. This means immediately cease all water usage while you check things out, as it could mean a problem with the pump or the disposal field.

Our system is rated for five bedrooms, which typically means 5-6 persons. They tend to over rate water usage when designing systems, so some say there is a buffer to support up to 8 persons if the tank is pumped yearly instead of every 3-5 years.

Our Sh*tty Luck

All the previous owners had less than 5 persons residing in the house. In fact, I think the max was 3 persons like us. The owners prior to us had the high water alarm go off once. The pump ended up burning out and it was replaced just months before we moved in.

The high water alarm sounded very loudly for us a month or so after moving in. The pump was not running when I peered in the manhole cover and the repair men found that the electric was fried. The pump survived, but we ended up having it rewired all the way back to the house. The experience taught me A LOT about septic systems. I became more water-wise and was a real stickler on planning our front yard landscape project to carefully avoid the leach field.

The second time the high water alarm went off was 8 months later. I was a pro by this time and could easily recognize that the pump was not running. The electric was again fried but fixed within a few minutes. The remaining problem was field one was not moving effluent (the waste water) at all and field two was doing so sluggishly. We ended up being on strict water conservation for a week prior to and following our leach field remediation, which consisted of hydrojetting the fields and treating them with Pro Pump bacterial cultures and root killer. They removed a lot of roots and biomat (black sludge), especially from field one. This was not inexpensive but less costly than relocating or replacing the leach fields, which is the next resort. I am skeptic but three different septic companies as well as the septic supply store told me that the treatment we received can remediate leach fields in about 90% of cases and prolong the life of the field for an additional five years or more in conjunction with water-wise living. I also flush a Pro Pump packet monthly. There is not a lot of evidence in favor or against these cultures and they are certainly no substitute for having the tank pumped regularly, but I figure it cannot hurt. We need all the help we can get.

What I Learned

Septic Dos

Have septic tank inspected regularly and pump every 2 to 5 years. This chart is handy in determining how often to pump based on the size of your tank and the number of regular occupants in your home. It also contains a chart with estimated daily flow. The University of Minnesota also has a useful tool found here.
Direct water from downspouts and roofs away from the leach field.
Use less water. Excessive water use is the most common cause of leach field failure as it does not allow enough time for the tank to do its job and solids end up getting flushed out into the leach fields, clogging the pipes with icky biomat. They estimate that each full-time resident uses 50 gal/day and daytime only visitors use 15 gal/day. This calculator is handy in discovering your household’s daily use.
Do keep your grass healthy and growing over the leach field to help absorb some of the water and prevent erosion.
Spread washing machine loads out and manually clean the lint traps regularly. Lint is another leading cause of leach field failure. Many recommend installing the Filtrol 160, an in line lint filter.

Septic Don’ts

Do not drive or park anything heavier than a riding lawn mower over the leach field or tank. You can compact the soil, cause damage to your lateral lines or sink right into the tank.
Do not plant trees or shrubs with large root systems near the leach field. If already present, remove or pour root killer (copper sulfate) into your pump tank every 6 mo. Root invasion from overgrown red tip photias was a major factor for us. This fact sheet from the University of Nevada contains good information on what you can and cannot plant near or in the leach field.
Do not cover the leach field with impermeable material such as landscaping weed cloth. Oxygen exchange is needed in the soil in order to break down and treat sewerage.
Don’t use a garbage disposal. The added solids and greases can damage your drainfield and cause you to have to pump the tank 50% sooner than if you compost your food scraps. We do have an InSinkerator, which is a septic friendly disposal that has an attached septic assist. It injects a biocharge enzyme with each use of the disposal. However, I rarely use it. My garden appreciates the compost 🙂
Don’t dispose of water from hot tubs or swimming pools in your septic. The chlorine will kill all your good bacteria.
Don’t flush any of the following in the toilet or down the sink: tampons, sanitary napkins, condoms, baby wipes (even the flushable kinds), napkins or kleenex, paint thinner, varnish, paint, diapers, cigarette butts, coffee grounds, grease or harsh chemical cleaners. Here is a list of the most septic friendly toilet paper and cleaning products. The goal is not to clog your tank or kill your bacteria.
Do not flush additives down your toilet. They are have not been proved to be beneficial and some can actually be harmful to your on-site sewerage system. We break the rule here in flushing our monthly ProPump. But it was recommended by our septic repairman who gets excellent ratings. ProPump also makes it onto this approved additives list I found, so I feel good about flushing it and the yearly cost is minimal.

Our Septic Friendly Efforts

Spread out laundry throughout the week and wash only full loads. We have a HE washer which uses 12.68 gallons per cycle (as opposed to a 40 gallon XL load in our old toploader). I have managed to cut down to 3 loads per week in this manner for 3 persons.
Attempting to utilize the dishwasher over handwashing + dishwasher . The autowash cycle on the dishwasher uses 3.3-5.2 gallons per load. I try to do only two full loads per week. Newer dishwashers are actually more effective if you do not pre-rinse the dishes. I have a hard time with this, so when I get the urge to hand wash, I fill up one side of the sink with soapy water and the other with cold rinse water rather than running the tap at 2.2 gallons per minute.
Install water-saving aerators on faucets and water-saving showerheads. With our kitchen at 2.2 gpm and 3 bathroom faucets at 1.5 gpm, we were already doing pretty well. I was able to obtain 1 gpm bathroom aerators for free from the City of Austin. They also have 0.5 gpm but they are only really useful for a quick hand wash. Not powerful enough to rinse toothpaste from the sink.
Install low flow shower heads. Our master bath had the most updated shower heads with one 2.5 gpm rain shower head and one 2.5 gpm optional hand-held. The other showerhead ratings were unknown so I picked up 1.5 gpm showerheads from the city with a soap up feature which allows you to temporarily stop the flow of water to soap up and then resume your shower. These are not the prettiest, so we will probably only use them when we have excessive house guests until we update with newer shower hardware. BUT they are a huge water saver at 22.5 vs 37.5 gallons for a 15 minute shower.
Check toilets for leaks using the dye test We already have low flow toilets (1.28 and 1.6 gpf) so we were lucky in that regard. Older toilets can use up to 4-6 gpf.
If it’s yellow let it mellow, if it’s brown flush it down. This is a practice which has always disgusted me. But when I heard it saves approximately 2, 190 gallons per person per year, I thought I’d give it a try. Some septic users take it one step further by throwing TP from #1 in the trash instead of the toilet. The verdict is still out on which is better or the environment.
Turn off the tap while brushing teeth or soaping up face. This saves 25 gallons per month for teeth brushing alone.
Be mindful when having overnight guests past your septic’s normal capacity. This is a helpful tip sheet for dealing with the holidays. We will be putting our own system to the test very shortly with a 19 person family reunion x 1 wk. We are scrambling to install an outdoor shower that will flow into the landscape beds, have stocked up on paper plates and plastic wear and have located the nearest laundry mat.