For most Massachusetts homes not hooked up to municipal sewers, septic systems provide wastewater treatment and disposal. However, if a system is failing, site limitations can make it difficult to replace it with another conventional system that will meet state standards. Innovative/Alternative (I/A) systems can help address these situations:

  • They are generally better than conventional septic systems at removing pollutants from wastewater before it goes to the soil absorption system (SAS).
  • An I/A technology should have a longer life.
  • I/A technology can also provide advanced treatment to reduce nitrogen content in wastewater.
  • New home construction near a water supply well or other nitrogen-sensitive areas may require nitrogen-reducing systems.

Whether your home already has an I/A system or you are thinking about installing one, it's important to get acquainted with the basics: what your alternatives are, how they work, what they cost to install and maintain, what is required to stay in compliance with Title 5 (the State Environmental Code), and where you can find additional information and assistance.

The Basics

An I/A system is any septic system, or part of one, that is not designed or constructed like a conventional Title 5 system. A conventional system has a septic tank, a distribution box or dosing mechanism, a soil SAS and a reserve area. Some examples of alternative systems are:

  • recirculating sand filters
  • aerobic treatment units
  • Wisconsin mounds
  • peat filters
  • humus/composting toilets
  • intermittent sand filters

I/A systems can perform as well as or better than conventional systems when their design, construction, operation and maintenance are in accordance with MassDEP's approval and the manufacturer's recommendations. 

At present, recirculating sand filters and humus/composting toilets are specifically approved for general use by Title 5, subject to certain conditions listed at 310 CMR 15.202 (RSFs) and 310 CMR 15.289 (humus/composting toilets). MassDEP has issued many approvals and certifications for I/A technologies, and reviews new technologies on an ongoing basis.

List of Title 5 I/A Technology Approval Letters || Summary of Approved I/A Technologies

Humus/composting toilets may be installed without a MassDEP permit provided that the proposed use meets the conditions in 310 CMR 15.289(3). Your Board of Health and MassDEP must approve any proposed use that does not meet these conditions.

No matter what use is proposed for a composting toilet, you must have a Disposal System Construction Permit doc format of Disposal System Construction Permit
pdf format of                             Form 2A - Disposal System Construction Permit                 from your local Board of Health before installing it.

Both local and state environmental officials involved in the approval process are responsible for ensuring:

  • that the proposed system meets local requirements, which may be more stringent than MassDEP's;
  • that the selected system will perform at least as well as, if not better than, a conventional septic system; and
  • that the installation is done in accordance with all the requirements of Title 5.

If you already have an I/A system, you need to know what kind of technology it uses, keep good records on the system's location, and be sure to operate and maintain it properly. MassDEP requires that owners of alternative systems have a maintenance contract with a specifically licensed individual or company, and the local board of health can require the owner to provide a copy of a valid operation & maintenance (O&M) contract.

Before considering an I/A installation

MassDEP must review and approve any I/A technology for use in Massachusetts. The local board of health also needs to review and approve plans for the technology. A qualified system designer who is either a registered professional engineer or a registered sanitarian prepares these plans. In certain instances, the site-specific local approval must then be sent to MassDEP for concurrence and final authorization.

No matter what type of system you want to install, you will need to work with a qualified designer to make the right decisions and to produce plans that can obtain local and, if necessary, MassDEP approval. Here are some initial questions to ask the designer:

  • Should I install an I/A system?
  • What are my technology options?
  • What are the local and state approval requirements?
  • How much will it cost me to install, operate and maintain an I/A system rather than a conventional one?

Once you have identified one or more specific technologies to consider, you should ask additional questions of the designer:

  • How many of these systems are operating in Massachusetts?
    • What does the performance data show?
    • What is the warranty?
  • What type of MassDEP approval does this system have?
    • Will I need MassDEP approval to install the system on my lot?
  • What are the sampling and testing requirements?
    • What will the operation and maintenance service contract cover?
  • Is there any information available on equipment or operating problems?

New construction

Title 5 has specific requirements for percolation rate, depth of soil, and separation from high groundwater. If your lot does not meet these requirements, you cannot use an I/A system for new construction. Although Title 5 provides flexibility in order to help property owners continue to use existing homes and businesses, new construction or increases in design flow must meet the design standards of Title 5.

If you are building a new house and would like to use a technology that does not currently have a MassDEP approval, the technology manufacturer may apply to MassDEP for Piloting or Provisional approval, or for General Use Certification. Or you may apply to MassDEP for approval to pilot the technology on your property. To pilot an alternative system for new construction, including an increase in design flow, you must show that the property could support a conventional system; this provides for a back-up in case the piloted system fails.

Buying a home with an existing I/A system

If you are thinking of purchasing a home that is not connected to a sewer, you should request a copy of the inspection report that Title 5 requires when a house is sold. This inspection is a requirement whether the house has a conventional septic system or an I/A system.

For either new or existing homes, you should ask about the septic system and whether it uses I/A technology. If it does, you should ask the owner or real estate agent the same questions that you would ask a designer. If they can't answer your questions, you should require that they either do the necessary research and get back to you or put you in contact with the designer of the system. Don't sign a purchase-and-sale agreement until you are fully informed about the type of I/A system in use on the property, as well as the related maintenance contract requirements, annual operating and energy costs, and maintenance history.

For more information

For additional information about I/A technologies for wastewater treatment and disposal, contact the MassDEP Regional Service Center that covers your part of the state:

Western (Springfield): 413-775-2214

Central (Worcester): 508-792-7683

Metro/Northeast (Wilmington): 978-694-3200

Southeast (Lakeville): 508-946-2714

On the Web:

Massachusetts Alternative Septic System Test Center

National Small Flows Clearinghouse