Septic System GHG Emissions
Challenges and Opportunities to reduce GHG emissions from
municipal and residential septic systems
Septic System GHG Emissions
Understanding Septic System Emissions
Reduction Strategies
Measuring Reduction
Understanding Septic System Emissions
• Decentralized waste-water treatment arrangement
• Anaerobic (traditional) septic systems and Aerobic Treatment Systems (ATS)
• Major GHGs produced by septic systems are CH4, N2O, and CO2
Understanding Septic System Emissions
Understanding Septic System Emissions
The global warming
potential of CH4 is 21
times more powerful than
CO2
Total GHG Emissions in the US, million metric tons (2007)
Understanding Septic System Emissions
Aerobic Treatment System (ATS)
• Oxygen present• Requires mechanical exposure
to air/atmosphere• Produces NO2, and CO2
Anaerobic Septic System (Conventional)
• No oxygen present• Relies on gravity• Produces CH4, CO2, and NO2
Understanding Septic System Emissions – Advantages
Aerobic Treatment System (ATS)
• Less odor, less CH4• Smaller drainage field
requirement• Greywater can be reused on
surface vegetation
Anaerobic Septic System (Conventional)
• Simple• Less Expensive• Minimal Maintenance• Common
Reduction Strategies - Overview
• Retrofit/Replacement– Direct GHG source reduction– Pairs with regular required maintenance
• Operational/Conservation– Indirect GHG reduction– Provides additional resource conservation
• Public Communication– Resident investment and self-enforcement
Reduction Strategies
Reduction Strategies – Retrofit/Replacement
Exhaust Vent Carbon Filters• Activated Carbon removes
methane from septic exhaust• Filters require regular
replacement and maintenance• Filters require unobstructed
pathways and correct installation
Retrofit/Replacement
Operational/Conservation
Public Communication
Reduction Strategies
Reduction Strategies – Retrofit/Replacement
Upgrade to Aerobic septic systems• Aerobic systems do not
produce CH4 (methane)• Aerobic systems require a
smaller drain field• Aerobic systems require
mechanical aeration and frequent monitoring
• Direct replacement or supplemental aeration septic tank
Retrofit/Replacement
Operational/Conservation
Public Communication
Reduction Strategies
Reduction Strategies – Retrofit/Replacement
BE CAUTIOUS: Aerobic retrofitting• Transition from anaerobic to
aerobic requires expertise• Biomat dissolution may create
rapid drainage flow rate• Aerobic circulation pumps may
agitate settled solids in the septic tank (sludge)
Retrofit/Replacement
Operational/Conservation
Public Communication
Reduction Strategies
Reduction Strategies – Retrofit/Replacement
Retrofit/Replacement SummaryStrategy NotesExhaust Vent Carbon Filters • MUST USE ACTIVATED CARBON
• Replace regularly (est. 1-2 years)• Correct installation/seals
Upgrade to Aerobic septic systems • Direct replacement of system• Supplemental aerobic septic tank
Aerobic retrofitting devices • Requires professional assessment of existing system and cautious implementation
Retrofit/Replacement
Operational/Conservation
Public Communication
Reduction Strategies
Reduction Strategies – Retrofit/Replacement
How could we make this happen?Strategy NotesEstablish County or municipal rebate program • Provide percentage or fixed-price rebate
for septic system vent filters, quantity limited per household
• Provide percentage or fixed-price rebate for septic system replacement
Private Partnership • Establish partnership with septic services company to provide products and services in exchange for some value (minimum # of units guaranteed, municipality recommended vendor, other publicity)
Public communication • Flyers, mailers, newsletter, article, other distribution to inform residents of benefits and opportunities
Retrofit/Replacement
Operational/Conservation
Public Communication
Reduction Strategies
Reduction Strategies – Operational/Conservation
Regular Inspections and Maintenance• Check on septic tank
digestion, pH, and sludge build-up
• Verify system piping and tanks are sealed airtight and no leakage is present
• Protect and maintain the drainfield
Retrofit/Replacement
Operational/Conservation
Public Communication
Reduction Strategies
Reduction Strategies – Operational/Conservation
Manage Household Generation• Lifestyle modifications reduce
hydraulic loading• Home appliance and plumbing
retrofits reduce hydraulic loading
• Avoiding harsh cleaners and garbage to protect the bacterial digestion and tank integrity
Retrofit/Replacement
Operational/Conservation
Public Communication
Reduction Strategies
Reduction Strategies – Operational/Conservation
Operational/Conservation SummaryStrategy NotesRegular Inspections and Maintenance • Inspections 1-2 years
• Pump out 2-8 years• Broken vent seals and leaks lead to fugitive
GHG emissions• Take care of drainfield
• Loading weight• Vegetation and growth• Over saturation
Manage Household Generation • Install low-flow fixtures• Encourage water use reducing behavior• Limit types of material disposed of• Limit bleach and strong cleaners
Retrofit/Replacement
Operational/Conservation
Public Communication
Reduction Strategies
Reduction Strategies – Operational/Conservation
How could we make this happen?
Retrofit/Replacement
Operational/Conservation
Public Communication
Reduction Strategies
Strategy NotesEstablish County or municipal rebate program • Provide percentage or fixed-price rebate
for septic system inspections or septic tank pumping
• Provide percentage or fixed-price rebate for purchase or installation of low-flow faucets, toilets, or kitchen fixtures
Private Partnership • Establish partnership with plumbing or fixture company to provide products and services in exchange for some value (minimum # of units guaranteed, municipality recommended vendor, other publicity)
Public communication • Flyers, mailers, newsletter, article, other distribution to inform residents of benefits and opportunities
Reduction Strategies – Public Communication
Broad Outreach Campaign• Statement by Town Supervisor
or Board issued to town• Direct mailing, including
newsletter flyers, postcards, checklists, or recommended vendors
• Social media activity or email with supplemental tools and resources
Retrofit/Replacement
Operational/Conservation
Public Communication
Reduction Strategies
Reduction Strategies – Public Communication
Targeted Public Awareness Campaign• Brief talks at local community
centers including churches or senior centers
• Table and flyers at farmers’ markets, school events, or town events
• Partner with local businesses like hardware stores to post information or hold special events
Retrofit/Replacement
Reduction Strategies
Operational/Conservation
Public Communication
Reduction Strategies – Public Communication
Health/Building Inspector Education• Train health and building
inspectors on signs of failing septic systems
• Provide speaking points for inspectors to share with home and building owners on inspections
• Flag inspected properties as exhibiting signs of septic system failure
Retrofit/Replacement
Reduction Strategies
Operational/Conservation
Public Communication
Reduction Strategies – Public Communication
Public Communication SummaryStrategy NotesBroad Outreach Campaign • Intended to reach all audiences
• General and non-specific• Less intensive than targeted campaign
Targeted Public Awareness Campaign • Intended to target specific audiences linked to septic system ownership and maintenance (general contractors, homeowners, etc.)
• Better saturation than broad outreach
Health/Building Inspector Education • “Train the trainers”• Municipal staff interacting with the public
can observe septic system issues and inform owners on potential solutions
Retrofit/Replacement
Reduction Strategies
Operational/Conservation
Public Communication
Reduction Strategies – Public Communication
How could we make this happen?
Retrofit/Replacement
Reduction Strategies
Strategy NotesPublic Statement • Formal statement of intent to reduce
septic system emissions published by municipal government/committees
Flyers/Mailers • Mailers to residents• Flyers in newspapers• Email distribution• Distribution through existing channels like
schools and municipal committeesElectronic Media • Informational postings on facebook,
twitter, or town website
Direct Outreach • Talks, events, or flyers at various churches, farmers’ markets, special events, school events, radio programs, or other venue
Operational/Conservation
Public Communication
Reduction Strategies – Public Communication
How could we make this happen? (cont.)
Retrofit/Replacement
Reduction Strategies
Strategy NotesPartner with businesses • Work with local hardware shops, general
contractors, home supply stores, or other businesses to distribute informational packets about septic systems
Empower Building and Health Inspectors and Departments
• Frequently interface with the public• Typically involved during new construction
activities and major renovations – ideal for educating contractors and owners
• Building and Health Department records can be adapted to include existence and condition of septic systems.
Operational/Conservation
Public Communication
Reduction Strategies - Recap
• Retrofit/Replacement– Direct GHG source reduction– Pairs with regular required maintenance
• Operational/Conservation– Indirect GHG reduction– Provides additional resource conservation
• Public Communication– Resident investment and self-enforcement
Reduction Strategies
Enforcement through Health, Building, and Zoning
Set Requirements for Septic Systems • Specifications or siting approval
established by Health Department
• Requirements for major rehab or new construction by Building Inspector
• Modify existing approval programs to also require update, retrofit, or replacement of outdated septic systems
Reduction Strategies
Public Communication
Operational/Conservation
Retrofit/Replacement
Measuring Reductions in Septic System Emissions
Measuring Reductions in Emissions
• Septic System Inventory– Number of septic systems– Type of septic systems
• Tracking Improvements/Upgrades– Rebate/financial incentives– New construction
• Parametric Estimation– Establish % improvement over baseline condition– Apply reduction based on number of improvements/upgrades
Key Resources
This presentation available at: www.midhudsoncsc.org
Additional Resources:• EPA SepticSmart
http://water.epa.gov/infrastructure/septic/septicsmart.cfm – for Government Officials http://water.epa.gov/infrastructure/septic/
• Catskill Watershed Septic Programs: http://www.cwconline.org/septic_program.html– http
://www.cwconline.org/septic_reahabilitation_and_replacement_program.html
• NY Water Environment Association http://nywea.org/ • National Environmental Services Center:
http://www.nesc.wvu.edu/subpages/septic.cfm • National Small Flows Clearinghouse (NSFC)
http://www.nesc.wvu.edu/wastewater.cfm • Environmental Facilities Corporation (EFC) offers several grant
programs for municipalities to fund wastewater infrastructure projects or http://www.efc.ny.gov/CleanWaterLoans
• NYS Water Resources Institute at Cornell University also provides additional resources, reports, workshops and other wastewater information on their website: http://wri.eas.cornell.edu
Roundtable Discussion / Review
How do we manage septic systems?
What do we need in order to manage them better?
What are our next steps?