Sources

The sources behind the numbers and rules on this site. Last reviewed October 2026.

• How to Care for Your Septic System, US EPA. Used for: Inspect at least every 3 years; pump typically every 3–5 years; when to pump; garbage disposals; water use.
• Types of Septic Systems, US EPA. Used for: How conventional, chamber, mound, aerobic, drip and sand filter systems work.
• Septic Tank Maintenance (EC 1343): pumping frequency table, Oregon State University Extension. Used for: Years between pumpings by tank size and household size.
• Septic Tank Pumping, Penn State Extension. Used for: Pennsylvania tank minimums by bedroom; additives not needed; pump when sludge reaches a third of tank depth.
• On-lot Septic System Inspections During Real Estate Transactions, Penn State Extension. Used for: Real estate inspection cost with required pumping; hydraulic load test cost.
• Septic tank capacity and sizing, Table 802.7.1, ICC model code via UpCodes. Used for: Model-code minimum tank sizes by bedroom (750 gal minimum).
• 15A NCAC 18E .0801 Septic Tank Capacity Requirements, North Carolina rules (OWPNC). Used for: 1,000 gal minimum; 120 gal/day per bedroom design flow.
• WAC 246-272A-0232 Septic tank minimum volumes, Washington State Legislature. Used for: 1,000 gal for up to 4 bedrooms, +250 gal per extra bedroom.
• LTAR 101: long-term acceptance rates by soil class, AQWA (summary of South Carolina rules). Used for: Soil loading rates by soil class; 120 gal/day per bedroom.
• How Much Does It Cost to Install a Septic System?, Angi. Used for: National average $8,016; cost by system type; perc test, permit, survey, riser and lid costs.
• Septic Tank System Cost, HomeGuide. Used for: Conventional system $3,500–$8,500; tank $1,000–$1,500; permits $250–$650; labor about 50%.
• Engineered Septic System Cost, HomeGuide. Used for: Aerobic, mound and sand filter system costs (high end).
• How Much Does a Septic Tank Cost?, LawnStarter. Used for: Install average $5,828; aerobic $10,200–$18,300; riser $300–$600; pump alarm about $475.
• How Much Does Septic Tank Pumping Cost?, Angi. Used for: National average $428; most pay $292–$565; $250 small tanks to $700+ for 2,000 gal.
• How Much Does It Cost To Pump a Septic Tank?, This Old House. Used for: Average $420 ($290–$560); hardened sludge $100–$300 extra; filter cleaning $100–$200; concrete tanks 40+ years, steel 15–20.
• Septic Tank Pumping Cost, HomeGuide. Used for: $300–$700; $0.30–$0.70 per gallon.
• How Much Does a Septic Inspection Cost?, Angi. Used for: National average $550; cost by inspection type; digging $50–$250.
• How Much Does Septic Tank Repair Cost?, Angi. Used for: Septic tank lid repair $150–$500.
• Septic Tank Repair Cost, HomeGuide. Used for: Repair prices by part; inspection $150–$450; pump replacement $500–$1,300; system lifespan 20–40 years.
• Drain / Leach Field Replacement Cost, HomeGuide. Used for: Replacement $3,000–$15,000; rejuvenation $1,000–$5,000; moving a field; lifespan 20–25 years.
• Perc Test Cost, HomeGuide. Used for: Hand-dug $200–$1,500; excavator $500–$3,000+; per-hole and professional fees.
• Who Does Perc Tests and What Do They Cost?, Angi. Used for: Average about $1,300; $300–$3,000.
• Mound Septic System, Angi. Used for: Mound install $10,000–$20,000.
• The Mound System (ID-163), Purdue Extension. Used for: How mound systems work and how to maintain them.
• Ejector Pump Replacement Cost, Angi. Used for: Ejector pump average $2,300 ($850–$3,500); labor $650–$1,200; grinder pump costs.
• Septic Pump Replacement Cost, Aquamatic (contractor). Used for: Effluent pump jobs about $1,650–$2,000; grinder $2,500–$4,000+.
• Septic Maintenance Cost in Texas, Texas Septic Guide. Used for: Aerobic maintenance contract $300–$500/yr; electricity $100–$300/yr.
• Choosing toilet paper for a septic system, Bio-Sol. Used for: Recycled and septic-safe paper; the mason jar test.
• What kind of toilet paper is safe for your septic tank?, Tidy Tank Septic Service. Used for: Wet strength, multi-ply paper, paper towels, tissues and wipes.
• Understanding tiny house systems, B&B Micro Manufacturing. Used for: Connecting a tiny house to an existing septic system or sewer.
• Maintenance of On-Site Sewage Facilities (Septic Systems), Texas Commission on Environmental Quality. Used for: Aerobic maintenance contracts, reporting every 4 months, homeowner maintenance after 2 years, chlorine tablets, pumping every 3–5 years.
• On-Site Sewage Facilities (Septic Systems), Texas Commission on Environmental Quality. Used for: Who regulates septic systems in Texas; local authorized agents.
• Onsite Sewage, Florida Department of Environmental Protection. Used for: DEP took over septic rules on July 1, 2021; county health departments still permit and inspect in most counties.
• Fla. Admin. Code R. 62-6.008, System Design Determinations, Florida Administrative Code (via Cornell LII). Used for: Sizing by bedrooms and building area; 900 gal minimum for blackwater tanks.
• Ohio Administrative Code Chapter 3701-29, Sewage Treatment Systems, State of Ohio. Used for: Ohio's statewide rules; operation permits issued by the local board of health.
• Operation and Maintenance Program, Darke County Health Department (Ohio). Used for: Rules effective January 2015; county O&M programs; pumping every 3–5 years.
• Time of Transfer, Iowa Department of Natural Resources. Used for: Inspection required before sale or deed transfer (Iowa Code 455B.172); public report database.
• Iowa Admin. Code r. 567-69.2, Time of transfer inspections, Iowa Administrative Code (via Cornell LII). Used for: Transfers exempt from inspection.
• Iowa Admin. Code r. 567-69.9, Iowa Administrative Code (via Cornell LII). Used for: Design flow of 150 gallons per bedroom per day.
• 30-A M.R.S. §4216, Subsurface waste water disposal; shoreland transfers, Maine Legislature. Used for: Inspection before buying shoreland property; seller's written statement; exemptions.
• 310 CMR 15.301, Title 5 inspection at time of transfer, Massachusetts regulations (via Cornell LII). Used for: Inspection within 2 years before sale, or up to 6 months after in bad weather.
• 310 CMR 15.223, Septic tank capacity, Massachusetts regulations (via Cornell LII). Used for: Tank at least 200% of design flow, never under 1,500 gallons.
• Michigan has the nation's weakest regulations for septic systems, Bridge Michigan. Used for: Michigan is the only state without uniform statewide septic standards.
• Michigan Septic Code, FLOW Water Advocates. Used for: 11 of 83 counties require inspection when a property is sold.
• Time of sale septic inspections can protect water quality, Michigan State University Extension. Used for: EGLE: conventional system lifespan 25–40 years; 4,297 failed systems reported in 2023.
• N.J.A.C. 7:9A-8.2, Septic tanks: capacity, New Jersey Administrative Code (via Cornell LII). Used for: 250 gallons per bedroom, never under 1,000 gallons; expansion attics count as bedrooms.
• N.J.A.C. 7:9A-3.2, New systems, New Jersey Administrative Code (via Cornell LII). Used for: Local board of health as the administrative authority.
• Chapter 246-272A WAC, On-site Sewage Systems, Washington State Legislature. Used for: Inspection every 3 years (gravity) or yearly (others); sale inspections from February 1, 2027; additive rules.
• Clearing up murky septic system transfer requirements, Geraghty Law Office (Colorado). Used for: Regulation 43 sets statewide minimums; 22 counties required transfer inspections (early 2026).
• Black Forest home sales no longer require a septic inspection, Colorado Home Finder. Used for: El Paso County ended its transfer inspection requirement on July 11, 2026.
• Septic Tank Additives, Ontario Onsite Wastewater Association. Used for: Types of additives and why they are not a substitute for pumping.

Septic rules are set by states and counties. For permits, setbacks and minimum sizes where you live, contact your county health department or your state's onsite wastewater program.