Melton Engineering and Homebuilders - Indian Creek Homes
 "Homes for the 21st Century"

Wastewater Treatment and Disposal

Wastewater treatment and disposal for single family residences have come a long way from the old fashioned septic tank. Back in the old days, the discharge from a septic tank often was simply dumped into a hole in the ground. This allowed for a very significant chance of contaminating either  groundwater or at least shallow surface water. Permitting authorities now require at a minimum a disposal field to attempt to minimize pollution from residential wastewater treatment. But in environmentally sensitive areas, this is not enough. A broad areas of sewage contamination in waterways in this area is apparent if one knows what to look for. excess algae growth in creeks and that telltale smell of septic tank effluent are two of the easier things to look for.  In severe cases black water will actually encroach into waterways. The black water is generally accompanied by the smell too.  This contamination is directly caused by septic systems.  Its smell is undeniable. Rampant algae growth is the result. In time, further more significant water pollution impacts will be realized. I have seen entire watersheds completely impacted by septic tank effluent.  Even though the septic systems may be functioning normally, traditional anaerobic systems can not remove enough nutrients to keep the algae from growing. These nutrients get into the groundwater and make their way into our waterways through seeps and springs. A green slimy creek bottom isn't natural in the Hill Country.

To do our part, we install only advanced wastewater treatment and disposal systems.  The aerobic treatment systems we use are identical to municipal treatment systems in everything but size.  The quality of water produced by these systems meets drinking water standards, and it has more than 5 times the quality of traditional septic treatment discharge.  And to further diminish the possibility of treated wastewater gett9ing anywhere close to groundwater, or an environmentally sensitive area, we dispose of our waster discharge through drip or spray irrigation. Normal wastewater disposal fields consist of a gravel bed or gravel filled trench with a perforated pipe.  When wastewater discharge enters this disposal area, it goes to the first hole in the perforated pipe and drains into the ground. The process is a little more complicated than this, and the results aren't quite as shocking, but compared to water disposal through irrigation, the technique is primitive. 

Irrigation techniques spread the water out evenly throughout the disposal area.  The discharge rate is 2 1/2 to 6 times less than in gravel trench or bed disposal. For example: A drip irrigation disposal area used in sensitive environmental areas has 6 times the amount of area available for disposal than does a traditional gravel filled trench.

This concept of wastewater treatment and disposal does cost more.  Sometimes, two to three times that of traditional treatment and disposal required by permitting authorities.  So why do it?  Over the years, permitting authorities have steadily increased their requirements for wastewater treatment and disposal.  why have they done this?  It is because, as our population increases, we generate, treat and dispose of more and more wastewater. The more our population increases and the closer we live together in cities and suburbs, the higher are the chances that residential wastewater treatment contamination will be evident.  That is why permitting authorities have steadily increase standards.  But Bureaucracies are always behind.  In this case as well as many, many others. To protect OUR environment, we have to make sure that WE are treating our environment appropriately.

It is my opinion, from working in the environmental industry for twenty years, that significant numbers of homes in sensitive environmental areas definitely upset the natural balance.  I will not allow my homes to contribute to this destruction of our environment by installing anything less than the best residential wastewater treatment and disposal systems available.

(The following information is an excellent study on the operation of on-site wastewater systems from Clallam County, Washington.)

Your wastewater treatment system is not a substitute for the trash can or a compost pile. Dispose of tissues, diapers, baby wipes, sanitary napkins, tampons, condoms, cigarette butts, and other solid waste with regular garbage and not down the toilet. Since these materials do not break down easily, they will cause your septic tank or the settling tanks in a municipal treatment plant to fill up faster.

Do not use a garbage grinder (dispose-all) in the kitchen sink; it adds to the load on the system. Excess grease, fats, and coffee grounds can clog your system.

Consider composting food waste and even some paper wastes as an alternative. Clallam County’s Cooperative Extension office (see Resource People) can provide you with information about composting.

Wastewater treatment systems are not designed to neutralize the wide variety of common household chemicals. Paints, solvents, acids, drain cleaners, oils, and pesticides can pass untreated through your system and contaminate the groundwater. Though generally safe when diluted, high concentrations or large volumes of water-soluble cleaners or bleach can harm septic tank microbes. (Click here for information on chemicals to keep out of septic systems; see Topic 5, "Managing Hazardous Household Products," for information on the proper disposal of hazardous chemicals.)

Chemical products advertised to "sweeten" or improve your septic system operation cannot replace routine pumping and may even be harmful. Buying and adding yeasts, bacteria, or enzymes is not necessary; there are already plenty of the right microbes digesting wastes in your system. Additives containing solvents to unclog your system can kill the microbes needed to digest wastes in your septic tank and drainfield. Furthermore, these solvents may contaminate your drinking water supply. For more information, see Additives for Septic Systems: or "Flushing Money Down the Toilet."

Average household water usage is shown in the chart below:

An average family of four sends about 300 gallons of water through its septic system each day. Reducing the flow of wastewater through the septic tank allows more time for solids to settle out and less chance of solid particles being carried over to the drainfield. Less water in the drainfield means better aeration for the soil microbes at work in the system. There are many steps you can take to reduce how much water you use. Here are a few:

For more tips on saving water, see Resource Publications below.

Worksheet 4.3: Septic or Sewage System Inputs

Use the table below to begin rating your risks relating to system inputs. For each question, indicate your risk level in the right-hand column. Although some choices may not correspond exactly to your situation, choose the response that best fits.

LINKS

Anaerobic Effluent 30 to 100 mg/l nitrogen as amonia   http://www.ces.ncsu.edu/plymouth/septic/98cardonaintro.html

Drinking water standard aerobic treatment system www.microseptec.com/images/pdfs/publishedpapers/nowra2000paper.pdf