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Home > Programs > Bureau of Environmental Protection > Office of Water Resources > Permitting > Onsite Wastewater Treatment Systems

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(after 1990)

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Onsite Wastewater Treatment Systems
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Updated: OWTS Repair Guidance in Critical Erosion Areas
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Permitting activities are divided into three main stages: site-suitability, design review, and construction inspection. Site-suitability is a preliminary stage which assesses the suitability of a parcel of property for on-site sewage disposal. Design review entails a review to determine a design's compliance with State standards, rules and regulations including setbacks to drinking water wells, water supplies, and sensitive water bodies. Proper design and installation is essential to protect public health and avert the potential adverse impacts of onsite wastewater treatment systems on water resources. Construction inspections are conducted during installation in addition to the inspections conducted by the Designer. Annually, the program undertakes approximately 2,300 suitability assessments, 5,000 permit reviews, and 11,600 inspections. Additionally, the program has developed a process for approving innovative septic system technology. As a result of 1997 revisions to the onsite wastewater treatment systems legislation, a licensing program (including training and examination) for private-sector professional designers and installers has been implemented in order to allow RIDEM staff to concentrate on major projects and proactive planning and policy development.

OWTS Rules
(eff. 7/16/14)
RI Design Guidance Documents for Non-proprietary Treatment and Leaching Systems

Guidelines for the Design, Use, and Maintenance of Pressurized Drainfields - November 2013
NOTE: This document addresses design, installation and O&M of pressurized drainfields. It incorporate Bottomless Sand Filters (BSFs) and Pressurized Shallow-Narrow Drainfields (PSNDS), which were previously covered in the "Guidelines for the Design and Use of Bottomless Sand Filters" and "Guidelines for the Design and Use of Sand Filters and Pressurized Shallow-Narrow Drainfields". Guidelines for the Design and Use of Sand Filters and Pressurized Shallow-Narrow Drainfields, Adopted April 2000, Revised March 9, 2010, September 14, 2010 and June 24, 2011, also referred to as "The Sand Filter Guidance Document (SFGD)"
Recirculating Sand Filter and Single Pass Sand Filter guidance relating to design, installation and O&M is available in this document. For the new Pressurized Shallow-Narrow Drainfield (PSND) Guidance, please consult the November 2013 document listed in the top portion of this cell.
The Onsite Wastewater Treatment System Program has created an e-mail list to distribute information on Department policies and rule changes. You can subscribe by sending an e-mail to: In the body of the message, include the following text: "subscribe owtsinfo". Leave the subject line blank. This is an announcement-only list so you will not be able to post messages to other subscribers. If you have difficulty subscribing or have other questions, email
Additional Links
New England Onsite Wastewater Training Program
USGS Water Table Information
OWTS Licensing Disciplinary Actions
Summary of R.I. Municipal Onsite Wastewater Programs

Rules and Policies
Rules Development:
Reports and Publications:
Nitrogen Loading in the Salt Ponds
USGS Salt Pond Groundwater Study

For more permitting information E-Mail:
Mohamed Freij (

For more installer licensing information E-Mail:
Linda Washington (

For more designer licensing information E-Mail:
Deb Knauss (

For more rules and policy information E-Mail:
Jon Zwarg (

For General Information 222-6800 • After Hours Emergencies 222-3070 • Disclaimer
rev. 12/15/15