Save $ - Keep Your Septic System Sweet! 2/14/15 (Printer-friendly copy)
How can you keep your septic system working well?
Conserve water. Send the septic system less than 50 gallons per bedroom per day, and under 10 gallons per bedroom per hour: Spread out baths, showers, laundry, etc. (8-min email@example.com gallons per minute=20gal, bath=washer=25-40gal, flush=1-7gal). Drain hot tubs & water beds elsewhere or over several days. Water softener salts may or may not hurt; minimize water with flow-based softener, not timer-based. Electronic softener may work. Reverse osmosis purifiers create 1-9 times as much waste water as the 2-15 gallons of clean water they deliver per day. Drainfield handles moderate flows forever (Long Term Acceptance Rate, LTAR). Wash water (graywater) has lots of bacteria & soap; it needs to go to septic or other treatment.
Don't flush what bacteria can't eat: Oil, coffee grounds, plastic (e.g. floss, diapers), clay-based cat litter, cigarette butts, paper except toilet paper. These accumulate & must be pumped out. Powdered detergents often include clays (zeolite, montmorillonite) which accumulate or clog soil. Hair flows through & clogs soil. Septic additives don't help & may hurt.
Don't flush cat feces in septic or sewer system: parasite hurts ocean species
Install a water meter to measure water use. (Biggest leaks can be toilets: Put food color in tank; does it appear in bowl?)
Find a pumper who will do the following (yellow pages under Septic; they'll find tank electronically if needed): Measure sludge & floating layers before pumping. After pumping, hose walls & look for leaks. Replace concrete outflow baffle (can corrode & let oil through) with PVC tee. Add a filter where water leaves tank. Have distribution box checked; it can tip or corrode. Have tank pumped every 3-5 years. Pump annually if you use a garbage disposal. While pumping, water flowing into tank from drainfield means field is waterlogged. Water trickling from house means a leak, or blockage.
What are alternative costs if your septic system stops working?
The symptom of a problem is water appearing at the lowest overflow point: a plumbing fixture or wet ground, not always odor.
FREE Conserve water as drastically as possible. Better than free: saves $$. Install water meter & read daily or weekly.
$0-500 Make sure storm water doesn't drain into septic system or onto drainfield.
$0-1,500 Go away for as many weeks as you can (vacation, friends, rent a house).
$1,500 Add a 2nd septic tank or replace with a 2-chamber model. Add a filter.
$1,500 Replace any septic tank that lets water leak in.
$2,500 Dig & divert flow to another drainfield if you have enough space.
$3,000 -9,000 Connect septic outflow to community drainfield.
$10,000 Replace your septic system with a home aerobic unit or other treatment.
$10,000 Replace soil & drainpipes. (Hydrogen peroxide does not fix drainfield.)
$25,000 Connect to public sewer & pay monthly bills.
How do septic systems work?
What can go wrong at each step?
Water & waste drain to a septic tank (1,000-2,000 gallons, concrete, fiberglass or polyethylene).
Internal baffles can corrode, break, or leak, so oil & paper wash into drainfield & clog it. Septic gas is dangerous; stay out & don't smoke near it.
Solids settle & light things like oil & paper float in the tank. Many ingredients are slowly broken down by bacteria.
(a) Sending water too fast doesn't leave liquid in tank long enough for solids & oils to separate out, & may exceed percolation rate of soil.
(b) Omitting pumpouts lets solids or oils build up until they can wash out to drainfield. See step 5.
Liquid flows out to a distribution box and then to 300-500 feet of perforated pipes in gravel beds in the soil (drainfield).
Trees & bushes within 20 feet of drain lines can clog pipes with roots. (Remote camera can inspect pipes.)
Liquid spreads through gravel & is then filtered by soil & treated by bacteria. Good bacteria digest nutrients & pathogens in the liquid & multiply, forming a valuable biological mat in pores of soil & gravel.
(a) Driving on drainfield compresses soil: water can't flow; bacteria can't grow.
(b) If water in drainfield (rain plus septic system) exceeds percolation rate of soil, water will back up in pipes or in soil.
Bacteria die after a normal lifespan, re-opening pores, and are constantly replaced.
Too many nutrients (from problem 2) make biomat grow faster than it dies; it becomes nearly impermeable, and water rises to surface or backs up into home. (Soil auger can take sample to inspect biomat. Infrared photos or sampling devices can measure flows & pollution.)
Clean liquid flows into groundwater, including any caverns or channels below ground. Some systems also reduce Nitrogen pollution
If pipes were installed too close above rocks, then unfiltered liquid can reach rock channels & pollute groundwater invisibly. If there is initially enough distance, biomat is a self-sealing barrier so invisible pollution does not start later.
Note that central sewers fail more massively: Pipes crack, treatment can fail, sludge goes on soil as thin as 6" over rock; pollution goes in streams & groundwater.
©Stewards of the Potomac Highlands, PO Box 1320, Shepherdstown, WV 25443, an environmental nonprofit. Donations welcome but not tax-deductible, since we lobby. Footnotes/sources are on PotomacStewards.com OK to reprint if you reprint this whole page.
Pipeline NSFC means the newsletter of that name published by National Small Flows Clearinghouse
Pipeline WVPSC means the newsletter of that name published by the WV Public Service Commission
 "Q+A, Septic Inspection" SFQ Winter 2004 v.5 no,1 p.40 and
"Gravel/Gravelless/Chambered Leaching Systems" SFQ Summer 2001 v.2 no.3, p.8 and
"Household Wastewater" http://www.ca.uky.edu/agc/pubs/ip/ip69/ip69.htm
 "Homeowner's Guide to Septic Systems" EPA-832-B-02-005, 2002, p.11
 "Q+A, Drainfield Inspection" SFQ Spring 2004 v.5 no.2, p. 42 and
"Letter II" " SFQ Fall 2004 v.5 no.4 p.19 and
"Water Softener Use Raises Questions for System Owners" Pipeline NSFC Winter 2001 v.12 no.1. Page 4 says calcium keeps the sodium chloride from clogging the drainfield. Page 6 says potassium chloride may hurt bacteria less. No research is cited on whether bursts of potassium or sodium hurt bacteria in normal anaerobic septic tanks.
 Electronic softener on incoming water pipe is designed to precipitate calcium ions into aragonite, which leaves water soft, does not cling to pipes, passes into drainfield and soil. Opinions differ whether it works. The effect of aragonite on drainfields is unreported, but it dissolves readily in slight acidity, which the biomat may have.
 "Reverse Osmosis for Home Treatment of Drinking Water" Michigan State Extension Service Bulletin WQ-24, Jan 1990 http://www.gem.msu.edu/pubs/msue/wq24p1.html or http://www.msue.msu.edu/msue/imp/mod02/01500611.html or http://www.ces.purdue.edu/extmedia/WQ/WQ-14.html and
 "the system never completely clogs" in "Q+A, How to Extend the Life of Your Drainfield" SFQ Summer 2003 v.4 no.3 p. 36 and
"Alternating Drainfields" Technical Overview SFBLTO01 p. 3, in SFQ Spring 2004 v.5 no.2, after p.28 and
"Wastewater Infiltration into Soil" Winter 2004 v.5 no.1, p. 29
 "Graywater Use" SFQ Winter 2001 v.2 no.1 p. 20
 Business use needs over-sized system, because of more organic waste per gallon and wider variations around the average flows. "The Best Wastewater Systems Consider Flow Rate and Waste Strength" SFQ Spring 2000 v.1 no.2 p.14
 "Mystery behind PPCPs" SFQ Winter 2004 v.5 no.1, p. 14 and
"Maine Passes Bill to Deal with Unused Medications" SFQ Summer 2004 v.5 no.3, p.8
 "Septic Tank Additives" SFQ Winter 2002 v.3 no.1, p. 27
 "Q+A, Drainfield Inspection" SFQ Spring 2004 v.5 no.2, p. 42
 APolyphosphate, Zeolite and Citrate in Detergents@ Kemisk‑Tekniska Leverantörförbundet Stockholm 1996,
AZeolites@ by Robert L. Virta http://minerals.usgs.gov/minerals/pubs/commodity/zeolites/zeomyb99.pdf
 "Septic Tank Additives" SFQ Winter 2002 v.3 no.1, p. 26 and
"Grease Traps" SFQ Spring 2002 v.3 no.2, p. 36.
There are allegations that Rid-XTM creates bubbles which lift solids out of the septic tank so they clog the drainfield. Any citations confirming or denying this allegation would be helpful. The National Library of Medicine says Rid-X liquid is 100% "Subtilisin" (proteolytic enzyme). The following are synonyms: Bacillopeptidase B; Subtilopeptidase C; Subtilopeptidase B; Subtilopeptidase A; Bacillus subtilis enzyme fermentation product; Bacillopeptidase A; Subtilisin; Bacillus subtilis carlsberg. The powder is 40-43% "Subtilisin"as above, 20-24% Calcium carbonate (Limestone), and the remainder unknown.
Washington state identifies Rid-X as not harmful to human health, and does not allow it to claim any reduced frequency of pumpouts http://www.doh.wa.gov/ehp/ts/WW/Additives.DOC
The manufacturer's website has little information http://www.reckittprofessional.com/customer_services/msds/dist/
 toxoplasma gondii, transmitted through the feces of cats, survives sewage treatment cbc.ca/news/canada/montreal/parasite-spread-by-cats-threatens-quebec-s-endangered-belugas-study-shows-1.4864194
 "Pumping Your Septic Tank" Washington Sea Grant Program 3/03 and
"Watertight Tanks" SFQ Summer 2004 v.5 no.3, p. 12
 "Effluent Filters" SFQ Winter 2003 v.4 no.1, p. 38
 "Offensive Odors Don't Always Mean Septic System Failure" SFQ Fall 2004 v.5 no.4 p.30
 "Alternating Drainfields" Technical Overview SFBLTO01 p. 7, in SFQ Spring 2004 v.5 no.2, after p.28
 Water flows in soil at a limited rate (percolation rate). If total of rain plus flushed water exceeds this rate, water backs up in pipes; reduce the load by sending rainwater elsewhere.
 Pipeline NSFC Summer 1995 v.6 no.3, p. 5
 "Many references ... suggest pressure dosing is equivalent to installing alternate drainfields"
in "Alternating Drainfields" Technical Overview SFBLTO01 p. 5, in SFQ Spring 2004 v.5 no.2, after p.28 and
"Q+A, How to Extend the Life of Your Drainfield" SFQ Summer 2003 v.4 no.3 p. 37 and
"Role of Biomats in Wastewater Treatment" SFQ Fall 2001 v.2 no.4, p.36
but "Letter III" says iron & sulfur accumulate in soil pores every time drainfield is saturated; SFQ Fall 2004 v.5 no.4 p.19
 "Alternating Drainfields" Technical Overview SFBLTO01 p. 6, in SFQ Spring 2004 v.5 no.2, after p.28
 "Gravelless System and Chamber System" SFQ Fall 2000 v.1 no.4, p 47 and
"Letter to the Editor" SFQ Summer 2004 v.5 no.3, p. 41 shows doubts about chamber system
"Soil Characteristics" Pipeline NSFC Spring 2002 v.13 no.2 p.5 and
"Chamber Systems are Easy to Install" SFQ Fall 2003 v.4 no.4, p. 50 and
"Wastewater Infiltration into Soil" Winter 2004 v.5 no.1, p.38 and
"Gravelless and Chamber Systems" Pipeline NSFC Summer 2001 v.12 no.3, p. 1
 "High-Strength Flows" Pipeline NSFC Fall 2003 v.14 no.4, p. 4 and
"Development of an Enhanced Performance Septic Tank" SFQ Winter 2001 v.2 no.1, p. 37
 "STEP System Clears the Air" SFQ Winter 2001 v.2 no.1, p. 28 and
"Small-Diameter Gravity Sewers" SFQ Spring 2001 v. 2 no.2, p. 24 and
"Sewage Disposal" Pipeline WVPSC Nov-Dec 2003 v.1 no.6
 "Maintaining Home Aerobic Units" SFQ Spring 2003 v.4 no.2, p. 36 and
"Composting Toilets" SFQ Summer 2004 v.5 no.3, p.42 and
"Incinerating Toilets" SFQ Winter 2004 v.5 no.1, p. 54 and
"Tablet Chlorination" SFQ Summer 2004 v.5 no.3, p.54 and
"Build Your Own Constructed Wetland" SFQ Fall 2004 v.5 no.4 p.19
"Graywater Use" SFQ Winter 2001 v.2 no.1 p. 20 and
"Biological Filtration" Technical Overview SFBLTO02, in SFQ Summer 2004 v.5 no.3, after p.28 and
"Matching the System to the Site" SFQ Winter 2001 v.2 no.1, p.14 and
"Quality Maintenance Key to ATU Performance in Texas" SFQ Fall 2000 v.1 no.4, p 8 and
"Taking the Gush Out of the Flush" SFQ Winter 2004 v.5 no.1, p. 22
 "Hydrogen Peroxide Not Recommended to Unclog Failed Drainfields" because it creates impermeable layer of fine sediment; SFQ Spring 2000 v.1 no.2 p.14
 Cost includes $16,000 pipes, $3,000 expanding treatment plant, $3,000 closing septic, $3,000 higher monthly bills
 Tire chips are an alternative to gravel "Tire Chips, a Growing Trend as Aggregate in Soil Absorption Systems" SFQ Fall 2003 v.4 no.4 p.14
 "Landscaping Options" SFQ Spring 2004 v.5 no.2, p. 21
 "Soil Absorption Systems" Technical Overview SFBLTO03, in SFQ Fall 2004 v.5 no.4, after p.32 has much information on drainfields. It says research shows that 24" of soil below trench, & above water table or rock (whichever is higher), are enough to treat effluent. It notes area of trench bottoms is average or peak gallons/day from the house, divided by gallons/square foot/day which the soil can absorb.
 "Alternating Drainfields" Technical Overview SFBLTO01 p. 3, in SFQ Spring 2004 v.5 no.2, after p.28 and
"In-Ground Dispersal of Wastewater Effluent" SFQ Spring 2003 v.4 no.2, p. 32 and
"Wastewater Infiltration into Soil" Winter 2004 v.5 no.1, p. 29 and
"Role of Biomats in Wastewater Treatment" SFQ Fall 2001 v.2 no.4, p.36
 "Q+A, Drainfield Inspection" SFQ Spring 2004 v.5 no.2, p. 42
 "Monitoring Effluent Plumes" SFQ Summer 2000 v.1 no.3, p. 40 and
"Septic System Performance Analysis Utilizing Color Infrared Aerial Photography, Berkeley County WV" by Environmental Research Inc, Linden VA, 1996 and
"Arkansas Sanitarian Uses Infrared Technology to Track Down Sewage" SFQ Spring 2000 v.1 no.2 p.22
 Rates of Nitrogen removal & energy use are at http://www.southriverfederation.net/index.php/news/blog/tags/40/
 "Think Septics Are Always Bad? Then You Don't Know Sewage" SFQ Fall 2004 v.5 no.4 p.19 reprinted from Bay Journal May 2004 and
"When Systems Fail" SFQ Fall 2004 v.5 no.4 p.20 and
West Virginia State Rules 47-31 App.B-A-2.2 expect well-designed new 8" diameter sewer pipes to leak 1,600 gallons/day/mile; and
Optimizing Operation, Maintenance, and Rehabilitation of Sanitary Sewer Collection Systems New England Interstate Water Pollution Control Commission 12/03 http://www.neiwpcc.org/omrmanual.htm "Many collection systems are maintained by a public works department charged with various functions, such as street, sidewalk, storm drain, and sometimes water utility maintenance. Money is usually spent where the ratepayer can see the results... The lack of proper maintenance has resulted in deteriorated sewers with subsequent basement backups, overflows, cave-ins, hydraulic overloads at treatment plants, and other safety, health, and environmental problems. As one of the most serious and environmentally threatening problems, sanitary sewer overflows - or SSOs - are a frequent cause of water quality violations and are a threat to public health and the environment." p. 1-2. " Since these sewers[crossing streams] are often in remote locations, they are susceptible to vandalism and can overflow for long periods of time without detection." p. 7-3 and
Report to Congress: Impacts and Control of CSOs and SSOs EPA 8/24/04 http://cfpub2.epa.gov/npdes/cso/cpolicy_report2004.cfm