Smithfield Wastewater Treatment Facility - 20 Esmond Mill Drive, Smithfield, RI  02917

Facility Overview

The Town of Smithfield Sewer Authority owns and operates the Smithfield Wastewater Treatment Facility (WWTF), which began operation in 1978. The facility has a design capacity of 3.5 million gallons per day, with an average daily flow of approximately 2.0 million gallons.

The WWTF provides advanced tertiary treatment, removing approximately 98% of organic matter, controlling odors, and meeting stringent nutrient removal requirements. The facility operates under a permit issued by the Rhode Island Department of Environmental Management (RIDEM) through the RIPDES Program, in compliance with the U.S. Environmental Protection Agency Clean Water Act.

Collection System

The Town's sanitary sewer collection system includes approximately 80 miles of underground sewer mains, ranging in size from 6 inches to 36 inches, along with gravity sewers, low and high-pressure force mains, and 12 sewer pump stations.

The collection system is operated by a contracted service provider under the oversight of the Town, utilizing GIS-based asset management to support maintenance, inspection, and long-term planning.

For any concerns, complaints, or emergency situations regarding the collection system, please contact the 24 hour emergency response number at 866-258-1922

For information related to Extension of Public Sewers within the Sewer Authority's district, please refer to the following requirements:

Smithfield Sewer Authority - Sewer Extension Policy Regulatory Requirements

Sewer Extension Policy General Requirements

Sewer Extension Standard Operating Procedures

Sewer Rates

Treated wastewater from approximately 8,500 customers is discharged to the Woonasquatucket River and ultimately Narragansett Bay. Smithfield's Wastewater Treatment District maintains one of the lowest sewer user rates in Rhode island, currently $450 annually for Fiscal Year 2026.

A comparison of sewer user rates statewide is available here:

2024 Rhode Island Sewer User Rate Survey

Operation & Industrial Pretreatment

The plant is operated by Veolia Water North America under a long-term operations and maintenance agreement with the Town. Treatment processes include Biological Notrient Removal (BNR) utilizing an A2O Process followed by tertiary treatment for zinc and phosphorus removal using the Actiflo tertiary treatment system.

The Sewer Authority also administers the Industrial Wastewater Pretreatment Program (IPP) to regulate commercial and industrial discharges to the municipal system. The program focuses on protecting treatment processes and infrastructure, with particular attention to Fats, Oils & Grease (FOG) and other regulated wastewater characteristics. 

Industrial Pretreatment Program - Restaurant Application

Industrial Pretreatment Program - Non-Restaurant Application

FOG Education

Fats, oils, and grease(FOG) are a leading cause of sewer blockages that can result in backups, property damage, and costly repairs. Proper disposal helps protect both private property and the public sewer system.

Educational Resources for understanding Wastewater:

Environmental Education & Outreach Co.

Take a Journey Down the Drain with Wastewater

Childrens Guide to Who Cleans Our Wastewater

Childrens Guide to Fats, Oils & Grease

 When it comes to getting to the root of sewer problems, please don't plant vegetation outdoors anywhere near your sewer line that services the building on your property.  In 20-years time tree and shrub roots can find their way into almost any sewer service line.