Title 5 - Septic Systems

Basic Guide to Title 5


The regulations governing the design, construction and inspection of septic systems is known as Title 5 (310 CMR 15.00). For new construction or repair of an existing system the steps are as follows:

Step #1: Percolation—Soils Evaluation

The percolation test demonstrates the rate at which water is absorbed into the surrounding soils. These are typically calculated in Minutes Per Inch (MPI). A hole is dug and filled with water. The engineer will then examine the hole to determine the rate at which the level of water recedes. For example, a 5MPI percolation rate means that it takes 5 minutes for one-inch of water to percolate into the soil. This figure is used in the calculation of your septic design plan.

The Soils Evaluation is an examination of the soils on your property to determine the high ground water table. Title 5 regulations govern the distance between the bottom of your sewage disposal system and the ground water table.

Percolation and soils evaluation tests can be performed year round.

Step #2: Plan Design and Review

Based on the above data and the number of bedrooms** in your dwelling, your engineer will design a septic system. The design is submitted to the Board of Health for review. No work can be done on the system until approval is granted by the Board.

Step #3: Septic System Installation

Upon approval of your septic design by the Board, a licensed installer is required to file for a Disposal Works Construction Permit for the installation of the system. Only a licensed installer may perform this work. A list of licensed installers is available by contacting the Board of Health office.

The system is inspected upon excavation, component installation, grading, and stabilization. It is the responsibility of the installer to contact the Design Engineer and the Board of Health for each of these inspections. Your installer is required to submit an Installer Certification Form along with slips for the stone and gravel used in the system. He/she is also responsible for signing off on the Certificate of Compliance form.

Step #4: Certificate of Compliance

After the system has been installed, your Design Engineer is required to submit an As-Built drawing of the system, the Certificate of Compliance Form, and the Engineering Certification Form. The As-Built drawing details the exact location and elevation of the system. The Certificate of Compliance Form is the legal document that certifies that the system has been constructed in accordance with Title 5 regulations. The Engineering Certification Form is unique to Northbridge but is a required document prior to release of the Certificate of Compliance.


Certificate of Compliance are valid for two (2) years.

*Bedroom - A room providing privacy, intended primarily for sleeping and consisting of all of the following:

(a) floor space of no less than 70 square feet;
(b) for new construction, a ceiling height of no less than 7'3";
(c) for existing houses and for mobile homes, a ceiling height of no less than 7'0";
(d) an electrical service and ventilation; and
(e) at least one window.

Living rooms, dining rooms, kitchens, halls, bathrooms, unfinished cellars and unheated storage areas over garages are not considered bedrooms. Single family dwellings shall be presumed to have at least three bedrooms. Where the total number of rooms for single family dwellings exceeds eight, not including bathrooms, hallways, unfinished cellars and unheated storage areas, the number of bedrooms presumed shall be calculated by dividing the total number of rooms by two then rounding down to the next lowest whole number. The applicant may design a system using design flows for a smaller number of bedrooms than are presumed in this definition by granting to the Approving Authority a deed restriction limiting the number of bedrooms to the smaller number.


The following companies are licensed by the Board of Health for septage hauling services in the Town of Northbridge.

  Able Septic Services(508) 435-7373
  ADC Septic(508) 883-9000
  Audet Septic Services (formerly Petrillo Septic)(508) 341-6025
  Baker Commodities, Inc.(978) 454-8811
  Ben's Container & Rubbish(508) 476-1500
  Chase/Harris Corp.(508) 865-2007
  Curtis Septic Service (508) 393-7234
  Gibson Septic Service(508) 473-4063
  Grants Septic Techs(508)  266-7550
  J.C. Parmenter Inc.(508) 435-3381
  J.L. Darling Sewerage Service(508) 278-2567
  J.L. Darling Septic Tank Pumping Co.(508) 278-9699
  Liquid Environmental Solutions(508) 236-6001
  Patriot Services(508) 697-9565
  Wall Trucking Inc.(508) 757-0940
  Waste Water Services, Inc.(508) 697-9974
  Wind River Environmental, LLC(800) 499-1682



Some Helpful Links

DEP Approved Soil Evaluators and System Inspectors

Frequently Asked Questions - Repairs & New Construction

Frequently Asked Questions - Buying or Selling Property with a Septic System

Title 5 Tax Credit Information