Common Septic System Installation

MistakesInspection Tips for Health Agents

Chris Sparages, P.E.Principal at Williams & Sparages LLC

Learning Objectives

• Review Title 5 Regulations Governing the Design, Construction, Repair, and Replacement of On-Site Sewage Disposal Systems

• Understand What to Look For When a Septic System is Under Construction

Chris Sparages, P.E.

• Registered Professional Civil Engineer in Massachusetts

• Over 25 years of Experience working for Civil Engineering Firms, specializing in Civil/ Site Design

• B.S. in Civil Engineering from Worcester Polytechnic Institute

• M.S. in Civil Engineering from Northeastern University

• Approved Soil Evaluator since 1998

Williams & Sparages LLC

• Co-Founded Williams & Sparages LLC in 2010

• Today we are 20 Strong

• Professional Engineers

• Professional Land Surveyors

• Registered Sanitarians & Approved Soil Evaluators

• Professional Wetland Scientists

• Great Support Staff and Interns

Williams & Sparages LLC

•Residential & Commercial Development Projects

•Primarily in the Private Sector

•We Design Many Types of Septic Systems

Septic System Design

• Conventional Pipe and Stone Systems

• Pump Systems

• Pressure Dosed Systems

• Innovative/ Alternative Technology Systems

• After a Septic System is Approved it now must be Installed, so we head to the field

Septic System Construction

•A quick word on Bottom of Bed Inspections

•Building Sewers

•Septic Tanks & Pump Chambers

•Distribution Boxes (D-Boxes)

•Soil Absorption System (SAS)

Building Sewer• Title 5 Defines a Building Sewer as “a pipe which begins

outside the inner face of a building wall and extends to an on-site septic system or a municipal or private sewer.”

Building Sewer

• Title 5 has requirements for Building Sewers.

• It must be sufficient to serve the connected fixtures and cannot be less than 4-inches in diameter.

• You must maintain a 10-foot separation between a building sewer and a water service.

• It must be laid on a compacted, firm base.

Building Sewer

• Title 5 has requirements for Building Sewers.

• It must provide for a minimum velocity of 2 feet/ second for the wastewater flow.

• This is achieved when laying a 4-inch pipe at a slope of at least 1 percent (1/8 of an inch per foot).

• A 2 percent slope is preferred (1/4 of an inch per foot).

Building Sewer

• Title 5 has requirements for Building Sewers.

• Sections must be laid in a straight line.

• When changing direction or where two sewers meet, a manhole, sweeping bend, or cleanout is required.

• They must be vented through a vent stack in the building.

• They must also comply with the State Plumbing Code.

Building Sewer

Building

Sewer at

Foundation

Riser Section Atop

Septic Tank

Septic Tank

Building Sewer

Manhole Riser Section

with Manhole Frame

and Cover

Inlet Tee Inside

Septic Tank

Building Sewer

Enters the Septic

Tank

Building Sewer

Building Sewer at

Foundation

Gap under the Pipe

Septic Tank

Building Sewer

Building Sewer at

Foundation

Gap under the PipeSeptic Tank

Septic Tanks

• 310 CMR 15.233

• Title 5 has requirements for Septic Tanks.

• 6-inches of crushed stone under the Tank

• The liquid depth from the outlet tee to the bottom of tank must be a minimum of 4-feet

• Risers required when Septic Tank is buried more than 9-inches

• Must be water tight

Septic Tanks

Access

CoverOutlet Pipe

Building

Sewer

Septic Tanks

Septic Tank

Access

Opening

Inlet Tee

Septic Tanks

Outlet Pipe

Outlet Tee

with Effluent

Filter

2-Compartment

Tank Baffle Wall

2-Compartment

Septic Tank

Tee at Baffle Wall

Septic Tanks

Riser Section

Septic Tank

Riser Section

Septic Tanks

Effluent Filter

Outlet Tee

ready to

receive

Effluent Filter

Access Cover

Septic Tank

Tee at Baffle Wall

Septic Tanks

Valve Pit

Pump

Chamber

2-Compartment

Septic Tank

Manhole Riser

Sections with Frame

and Water Tight

Cover at Surface

Distribution Boxes (D-Box)

• 310 CMR 15.232

• Title 5 has requirements for D-Boxes.

• 6-inches of crushed stone under the D-Box

• Distribution Lines leading from the D-Box Must be at the same elevation

• Risers required when D-Box is buried more than 9-inches

• Velocity of influent must be controlled (>8% slope or when being dosed)

Distribution Boxes (D-Box)

Septic Tank

D-Box

Distribution Boxes (D-Box)

Inlet Pipe

Outlet Pipe

Speed

Leveler

Grout Pipes where

they pass through

D-Box

Plug Unused

Openings

Distribution Boxes (D-Box)

Outlet Pipe

6-inches crushed

stone under D-Box

Cultec Chamber

Distribution Boxes (D-Box)

Inlet Pipe

Inlet Tee

Speed

Leveler

Distribution Boxes (D-Box)

Outlet Pipe

Baffle

Wall

Inlet Pipe

Distribution Boxes (D-Box)

Outlet Pipe

Speed

Leveler

HDPE D-Box

Magnetic

Tape

Distribution Boxes (D-Box)

HDPE D-Box

HDPE Riser Sections

Distribution Boxes (D-Box)

D-Box

D-Box Riser Section

& Frame for Cover

Distribution Boxes (D-Box)

Septic Tank

Light Duty Cover

over D-Box

Distribution Boxes (D-Box)

Pipes

Grouted

Outlet Pipes

Plug Holes not

being used

Heavy Duty

Cover (H-20)

Soil Absorption Systems (SAS)

• 310 CMR 15.240

• Title 5 has requirements for SAS.

• 4-feet of naturally occurring pervious soil

• Venting to the atmosphere under impervious surfaces

• Final Grading must slope away from the SAS

• Minimum of 1 Inspection Port Required

• Title 5 Sand required for filling to grade

Soil Absorption Systems (SAS)

Septic

System

Trench

Larger Washed

Stone Covered

with Peastone

Inspection

Port

Soil Absorption Systems (SAS)

Septic System

Trench

Larger Washed

Stone Covered

with Peastone

Inspection

Port

Septic System

Vent

Vent Header

Pipe

Soil Absorption Systems (SAS)

Distribution

Pipe

SAS in Field

ConfigurationInspection

Port

Septic System

Vent

D-Box

Soil Absorption Systems (SAS)

Cut off trench

Grade Drops off

Necessitating

the Barrier and

WallImpermeable

Barrier

SAS just out of

View

Soil Absorption Systems (SAS)

Cut off trench

Grade Drops off

Necessitating

the Barrier and

Wall

Impermeable

Barrier

SAS just out of

View

Soil Absorption Systems (SAS)

Header Pipe for

Vent

Inspection Port

SAS in Field

Configuration

Using Cultec

Chambers

Soil Absorption Systems (SAS)

D-Box

Pipe from Septic

Tank

SAS in Field

Configuration

with Pipe and

Stone

Filter Fabric

Ready to Cover

Field as an

Alternate to

Peastone

Soil Absorption Systems (SAS)

Lateral Piping

for Pressure

Distribution

SAS in Field

Configuration

with Pipe and

StoneInspection Port/

Valve

Squirt Test

Underway

Soil Absorption Systems (SAS)

Inspection Port

SAS in Field

Configuration

Using Cultec

ChambersD-Box

Magnetic

Marking Tape

As-built Checklist Form

Summary/ Recommendations

• Title 5 discusses the design, construction, repair, and replacement of on-site sewage disposal systems in great detail (KNOW THE CODE).

• Don’t be afraid to ask questions, installers and engineers have a lot of experience.

• Document your observations with field notes and photographs.

• Be sure to follow up with installers to confirm that missing items have been addressed.

Common Septic System Installation

MistakesInspection Tips for Health Agents

Chris Sparages, P.E.Principal at Williams & Sparages LLC