Educating Homeowners about Septic Systems
Len Gilstrap, RSCarteret County Health
Department
Carteret County Onsite Inspection and Tracking Program
EPA Section 319 Program Grant
Regulations
Onsite systems permitted under the provisions of Laws and Rules for Sewage Treatment and Disposal Systems (15A NCAC 18A .1900)
http://www.deh.enr.state.nc.us/osww_new//images/Rules/1900RulesJune2006.pdf
Purpose
To allow the continued use of wastewater systems that are installed in a proper manner and suitable soils so they do not have a detrimental affect on the public health and environment through contamination of land, groundwater and surface waters.
Risk Management
Rules for onsite wastewater systems are based on the risk associated with the proposed application.
Risk of contamination is enhanced with limited suitable soils or space, higher flows, higher waste strength, proximity to drinking water supplies, and water bodies.
Site Evaluations
Topography Soil characteristics Soil wetness Soil depth Restrictive horizons Available space
Site Suitability
Based on site evaluation results Wastewater flow Wastewater characteristics Setbacks to wells, water bodies,
ditches, property lines, etc.
Depth of drainfield and water table
Minimum 12 to 18 inches separation between bottom of trench and groundwater, even during wet times of the year
Aerobic (air) soil removes bacteria
Type of Soil
Sandy – too fast and not purified Clayey – too slow and poor
treatment (ponds) Uniform texture, yellow, yellow-red
or bright red in color Gray soil indicates anaerobic
conditions
Septic System Responsibility
Belongs to the owner Protect your investment Replacement cost = thousands $
Septic System Failures
Unpumped and sludge filled tanks Clogged drainfields Hydraulic overloading Landscape modifications of
drainfield area Ageing systems, old technology
Septic system failure can result in contamination of land, surface waters, and ground waters which causes human disease through direct consumption, direct or recreational contact or ingestions of contaminated shellfish.
Why Do We Care?
Conventional System Maintenance
The typical onsite septic system consists of a septic tank and a soil absorption (treatment) drainfield.
Sounds Simple?Wow – Do we have something to tell you!
Conventional Septic System
No Operator Required What do you know about your
system? What do you need to know about
your system? What can you do to protect your
system and investment? Proper septic system management is
key to protection of environment, investments, and public health.
Drainage and Landscaping Surface water diversions for foundation
drains, driveway, gutters and other paved areas
Heat pumps and water softeners, and irrigation systems
System area mounded to shed water Settled area and depressions filled Open ditches and outlets
Water Use
Drainfields designed for 120 gallons per bedroom/day
Exceeding design capacity may cause system to fail
Reduce water use by:
Checking toilets and faucets for leaks
Use 1.6 gal. (or less) per flush toilets
Use faucet aerators at sinks and flow reducer nozzles at showers
Limit length of shower to 10 minutes or less
Reduce water use by:
Do not fill bathtub with more than 6 inches of water
Do not wash more that 1 – 2 loads of laundry per day
Match water load to size of load being washed
Do not use dishwasher until it is full
Garbage Disposal? Doubles the amount of solids added to
tank Increases solids to drainfield due to
suspended solids Suggest putting most of table scraps in
trash Restrict use when possible Increase frequency of pumping
Grease and Oil?
Greases, creams, butter, cheeses and cooking oils clog soils
Additives to break down grease are not recommended. They tend to keep grease and oils in suspension while in tank and become solid in the drainfield.
Drainfield replacement always required
Cleaning Products?
Use biodegradable products when possible
Use moderate amounts of cleaners Do not pour solvents or other
chemical down drain Do not use toilet cleaners meant to
be placed in the toilet tank
Cleaning Products?
Improper use of cleaning products and chemicals kill bacteria in the septic tank and the drainfield
DO NOT FLUSH: paints, varnishes, thinners, waste oils, photographic solutions, pesticides
Solid Waste?
Do not put items down the drain that may clog septic tank or other parts of the system
Cigarette butts, feminine products, condoms, disposable diapers, paper towels, facial tissues, egg shells, coffee grounds, dental floss, kitty litter, plastics
Septic System Protected from Damage? Prevent soil erosion from drainfield area Protect turn-ups on LPP’s from mowers Keep vehicular traffic off system Maintain natural (downslope) drainage
away from system Do not build over drainfield or repair
area Locate system area prior to telephone
or cable installation
Vegetation around System
Trees and shrubs closer than 100 feet to system may cause problems
Root infiltration into tanks, pipes and drainfield
Do not put water loving trees near drainfield
Keep plantings away from tank openings
Is Septic System Accessible?
Do not cover any part with asphalt or concrete
Keep all construction away from system
For proper function and maintenance entire system must be accessible
Protect repair area
Pump that Tank
Use Table to determine pumping frequency
Inspection of solids and scum in tank is best method to determine if pumping is needed
Rule of Thumb: Pump if outlet end has 12 inches of solids and/or 4 inches of scum
Septic Tank
Effluent Filter
Image courtesy of USEPA
One Compartment tank
NC Rules require two compartments
Number of Years for Pumping your System
Tank size
(gallons)
Number of people using the septic tank system
1 2 4 6 8
900 11 5 2 1 1
1000 12 6 3 2 1
1250 16 8 3 2 1
1500 19 9 4 3 2
Find the tank and uncover opening
Use only approved wastewater haulers
Remove lid. This tank is past due for maintenance.
The pumper will break up the solids and mix with liquid so the entire contents of the tank can be removed.
Restoring the yard to the prior condition is not always possible. To prevent disturbance of landscaping a riser should be installed on the tank to allow for easy access.
Pump that Tank
Pump out both sides of septic tank The type of toilet paper, the
cleaning products, along with the habits of the system owner will affect how frequently a tank needs pumping.
Inspect annually
Pump that Tank
Good time to clean effluent filter
Improve the System Add effluent filters to older systems Add risers to tanks that require digging
up to inspect Add aluminum lids to pump tanks
openings and effluent filter openings Add float trees Contact septic system contractor or
certified operator to make improvements.
Risk Management
Higher risk applications require: Increased vertical and horizontal
setbacks from surface waters, water tables, property lines, wells, etc.
Higher levels of treatment
Risk Management
New wastewater technologies are quickly overcoming many limitations by creating systems with advanced pretreatment.
Risk Management
Septic tank influent350 mg/l BOD200 mg/l TSS
Pretreated effluent<10 mg/l BOD<10 mg/l TSS
Advanced pretreatment systems can produce effluent qualities that require less separation to ground waters, surface water and smaller disposal areas.
Peat Biofilter
Type B Peat Biofilter
Recirculating Sandfilters
Recirculating Sandfilter
Bioclere Pretreatment Filter
Bioclere
Filter Media
Advantex Pretreatment System
Filter media of an Advantex
Risk & Responsibility
More complex wastewater systems require more monitoring and management
Alternative & Innovative Systems Require contracts with certified
operators for operation and maintenance of system
Contract must be retained for as long as the system is required
Operation Permit specifies frequency of inspections
Health Department inspections and permit renewals
Owner Responsibilities Be knowledgeable about system
and it’s operation and maintenance requirements
Be supportive of Operator and maintain contract
When selling property provide new owners with information on septic system
Operator Responsibilities
Check septic tank and pump tank for solids
Inspect drainfields for adequate cover, surface water diversions, and surfacing effluent
Purge drainlines, check and set floats and pressure head
Operator Responsibilities
Check alarm, record readings in control panel, adjust timer settings
Perform performance measurements
Control Panel
Operator Responsibilities Use performance measurements to
evaluate system performance Take preventative measures when
deficiencies are noted Provide repairs when needed Available when needed Notify owner and health
department of condition of system
Alternative & Innovative Systems
Systems are more sensitive to water use, detergents, cleaning products and oils and greases
Replacing the system will be expensive – protect it now.
The Future Ignorance and neglect of your
septic system will insure costly, difficult and disruptive repairs.
Preventive maintenance rewards and protects your investment
Proactive governments can assist property owners to assure appropriate maintenance is provided.
“Management efforts at the local level can help assure these elements of infrastructure are managed positively and as assets which protect community values and investment, homeowner investments, public health and environmental quality.”
Dr. A.R. Rubin
Opinion Paper for Carteret County /Pine Knoll Shores Wastewater Management Workshop
References
USEPA, 2005; Onsite Wastewater Treatment Systems Manual, EPA 625-R-00-008
USEPA, 2005, Handbook for Onsite and Decentralized System Management, EPA 832 D 05 016)
USEPA, 2002, A Homeowner’s Guide to Septic Systems; EPA 832-B-02-005