Septic Systems in Pine Mountain Lake

Many people who buy in the Groveland / Pine Mountain Lake area have no prior experience with Septic Systems.  This article is intended to familiarize you with the basics of septic systems and to help you weigh the benefits and disadvantages of septic as compared to sewer.

How the Septic System Works

A septic system uses natural processes to treat and dispose of the wastewater generated in your home. It typically consists of a septic tank and a leach field, or "soil absorption field". The septic tank provides the first step in treatment. As wastewater flows into the tank, most solids, greases, and oils accumulate on the surface where bacteria breaks them down.  Solids that do not break down settle to the bottom to form a sludge layer.  The liquid wastewater (effluent) from the tank flows into gravel-filled trenches in the leach field where it is distributed via perforated pipes and then further treated by bacteria and the natural soil system.

The septic tank provides some biological treatment of the sludge and scum layers that accumulate there. More treatment occurs in the leach field where the effluent enters the soil and is treated as it percolates to the groundwater. The soil acts as a biological and physical filter to remove harmful substances, including disease-causing bacteria and viruses, toxic organics and other undesirable wastewater constituents remaining in the effluent.

Typical Septic System

Care for your Septic System

The average septic system will last from 30-40 years; but with proper care, they may last quite a bit longer.  One of the enemies of the septic tank and system is tree roots, so rule #1 is to not plant trees near your tank or leach field. Also avoid driving over or parking vehicles on your leach field.

The biggest enemy of septic tanks, though, is leaks from toilets.  A septic system is made to accept only intermittent flows of water.  Even a brand-new septic system will quickly fail if it receives significant water twenty-four hours a day.  A leak of twenty gallons an hour equals four hundred eighty gallons in twenty-four hours.  Septic systems are designed with expected water usage of fifty gallons per day per person with a maximum of two persons per bedroom (A three-bedroom system is designed with an expected maximum flow rate of 450 gallons per day).

Too much water in the system can interfere with the digestion process of the tank and send solids that have not been broken down into the leach field, and that can be big trouble for the septic system.  So, conserve water and stay on top of any suspected toilet leaks and have them fixed immediately!

Additionally, there are a few items that you just don’t want to get in your tank.  Never flush cat litter, disposable diapers, sanitary napkins, tampons, paper towels, dental floss, facial tissues, cigarette butts, or similar items down the toilet.  You should minimize the use of your garbage disposal and avoid oil, fats, coffee grounds, bones, or eggshells from going down your drain; consider installing a top-of-the-line disposal, which will grind waste into smaller particles that break down more quickly when they reach the system, but you still should avoid the above-mentioned items in your disposal.  Bones for example, can be ground down by a good disposal, but they will not be eliminated by the bacterial process of your septic system and will contribute to your tank's sludge layer.  You also want to avoid getting powdered detergent in your tank, so always use liquid detergent for dish and laundry washing.  Lastly, avoid the overuse antibacterial soap or strong cleaners, especially those with bleach in them, as these may kill the bacteria essential to your septic system.

There are many myths about “seeding” your septic system including advice to add yeast or “septic enzymes” being marketed, which will supposedly help in the decomposition of waste and/or eliminate the need to pump the tank, but most experts agree that they don’t really help.  The bacteria that are a byproduct of human waste are sufficient to do the job on their own.  Cellulase based septic enzymes, such as "Rid X", will help in the decomposition of cellulose (toilet paper/tissue), but most septic engineers recommends that you NOT use them, as they increase TSS (total solids in solution) that go out to the leach field.

The bacteria in the septic tank eat and digest most of the waste.  But the tank must be pumped regularly to remove the accumulated solids.  If it isn't, the tank will fill with sludge and the solids which will eventually be washed out into the leach field.  There, they will quickly clog the soil and eventually cause the septic system to fail.

The health department recommends pumping out the tank every 3 to 5 years.  The purpose of pumping out the tank is to remove accumulated solids and sludge. These solids can and will stop-up the soil where the wastewater is to be absorbed.  If you have a larger tank and/or the house is not occupied full time or by a lot of people, you could possibly go as much as 5-7 years without pumping, and I have seen many go much longer.  Pumping of the tank will typically cost from $450-500, depending on tank size.

Septic System Inspections

Inspections are relatively inexpensive ($275-350), but if the tank is buried deep (common with older homes) you could pay $200-$350 for excavation fees.  Some local septic companies insist on pumping out the tank in order to inspect (they make more money). But COWA / NAWT (septic engineer) guidelines more often than not permit tank inspection without pumping, and one local septic contractor, All Septic Co., is willing to inspect without pumping if the tank falls within those guidelines.  So, they are my preferred inspector in our area.  Purchase agreements locally are usually structured so that buyers pay for inspection (and evacuation of dirt to access tank, if necessary).  If pumping of the tank is required, the seller is usually asked to pay for it.  As we like to say locally, "when you move, you take your sh%t with you" :).

The purpose of the inspection is to:

    1. Confirm that there is proper draining from the house to the septic tank.

    1. Verify the integrity of the tank and confirm that there is no tree root intrusion or leakage.

    1. Confirm that there is proper draining from the septic tank to the leach lines (they will pump 150-160 gallons of water into the leach field to make sure that it does not back up).

For further info on septic systems contact: Kevan Wilson, All Septic Company (209) 532-1437.

Septic vs. Sewer in Groveland and Pine Mountain Lake

If you come from an area where most homes are on sewer, you may be a little intimidated by the idea of using a septic system, but they do have one significant benefit over sewer and that is cost.  Sewage bills in Pine Mountain Lake range from $105-110 per month.  Septic Systems are free!  Properly maintained, they can last 30-40 years or longer.  But when they do fail, you will be hit with a big bill.

At present, Groveland Community Services District provides sewer service to about one third of Pine Mountain Lake (most of the service is to homes that are near the lake or golf course).

There is now a Tuolumne County Ordinance that states that properties located within 300 feet of an existing public sewer disposal system may be required, if feasible, to extend the disposal line and connect to the service (100 feet for properties that slope downhill from the sewer connect area).  Such determination is made by the Tuolumne County Environmental Services/Health Department and Groveland Community Services District at the time of application for a sewage disposal and/or building permit.  So, if you are in a sewered area, and try to do any work to your septic system or home which requires a permit, they may require you at that time to connect to sewer.

One disadvantage of septic is that you will not be able to build on or near the tank or leach field.  You must avoid building within 5 feet of the tank and 8 feet from the leach field.  And you should not concrete over the tank or leach field, park vehicles on top of them, or plant trees on or near them.  Additionally, the plot plan you submit for building additions or new construction must contain an expansion area, which means space to put an entirely new leach field if the first one is saturated after extensive use – thus, more land area that you cannot build upon, and more land area that must be deemed suitable for a leach field.

There are even more potential concerns for septic installation.  For example, if your property contains a “DPA” (drainage protection area), you will need to plan your septic system around it; and if your neighbor happens to have a cut bank that is near your property boundary, that may affect leach line and "expansion area" location possibilities as well.

To summarize; a septic system can be a very efficient and cost saving means of sewage disposal, but precautions must be taken when buying a property with septic, or a lot where septic is a requirement or option.  As your real estate broker, I will refer you to a choice of professional septic specialists who can address all of the issues addressed in this summary as they relate to the property that you are considering purchasing.

This article was designed to provide a subjective overview of septic system care and considerations, but the author recommends that you only rely upon the advice of a COWA / NAWT certified septic contractor for care and maintenance of your septic system.