STS Construction Guidelines

SEWAGE TREATMENT SYSTEM (STS) CONSTRUCTION GUIDE

Carefully follow all conditions stated on the front of the permit.

Footer drains, gutters, and sump pumps cannot drain into or on top of the septic system. Do not install system when soil is wet. Do not disturb STS or replacement area. MINIMUM ISOLATION DISTANCES

• 10 feet to property/utility line, water line, driveway, & buildings. ■ 25 feet to creek or escarpment.
• 50 feet to water supply source, river, or lake.

BUILDING SEWER

• 4-inch schedule 40 or equivalent (ASTM D 2661 or ASTM D 2665).
• Minimum 1/8 inch per foot of fall and sleeved through foundation wall.
• Minimum of one 4” cleanout with a screw cap required. Cleanout required every 75 feet thereafter and/or at any turn in the pipe exceeding 45°.

TANKS, PRETREATMENT UNITS & DISTRIBUTION DEVICES

• Must be installed level with correct bedding and backfill.
• Inlet & outlet pipes must be level, properly supported and installed with approved fittings (no concrete or mortar).
• Riser(s) with secured cover over each compartment extending at or above grade.
• All septic tanks must be 2 compartment with a NSF approved outlet filter and inlet baffle or tee.
• Install distribution device minimum 5 feet from tank or pretreatment unit using minimum 3000 lb crush pipe.
• Minimum 5 foot of pipe after all distribution devices and 2 feet from drop boxes.

PRETREATMENT COMPONENTS

• All pretreatment units must be approved by the Ohio Department of Health.
• BOD/TSS approval is for soil absorption sizing reduction only. Units that treat <10K fecal coliforms allow for one foot of soil depth credit and units that treat <1K fecal coliforms allow for two feet soil depth credit.
• NPDES units must have telemetry or pump lock and 8" sampling box with inlet pipe 6" higher than outlet pipe.
• All pretreatment components require maintenance contract with a registered service provider for life of system.

LEACH FIELD

• Do not install leach in wet or frozen soil.
• Begin leach min. 5 feet from distribution device and 2 feet from drop boxes using min. 3000 lb crush pipe.
• Bottom of trench or bed installed level on contour.
• Distance between trenches minimum 10 feet on center unless otherwise specified on the permit.
• Bottom of trenches minimum 2 inches and maximum 18 inches below natural grade. See permit for exact depth.
• Install 4-inch inspection port with cap 10 feet from end of each trench.
• Approved leaching products or washed gravel meeting AASHTO M 43 size with 4-inch pipe with holes (no slots).
• For 12" tall trenches use 4" gravel below pipe, 4" with pipe and 4" on top. For shallow trenches use 2 inches below the pipe, 4 inches with the pipe and 2 inches on top of the pipe.
• When required, cover leaching trench with geotextile fabric or straw.
• Divert gutters, footer drains, and water conditioner backwash away from leach field.
• After final approval, cover with 6 inches topsoil (no clay) and seed with grass as soon as possible.

LIFT STATIONS & PUMPS

• UL or CSA listed. Pump should run minimum 60 seconds for each dose.
• Install weephole or checkvalve, a quick disconnect and visual and audio alarms.
• Sewage effluent or grinder pump only and wiring must meet the National Electrical Code.
• Do not install the control panel inside the lift station or riser.

INTERCEPTER DRAINS

• Drain depth can be no deeper than the restrictive layer and minimum 6 feet up-gradient from absorption area.
• Fill drain with gravel or approved pipe to within 6" of surface, cover with straw then topsoil.
• Discharge end must be rigid pipe and minimum 4” above grade or water level with an animal guard.

AS-BUILT DIAGRAM

• Remit signed and dated as-built diagram at time of final inspection.
• Include manufacturer or supplier O&M instructions.