Perc Tests and Soil Evaluations in Rhode Island

Called here: Soil Evaluation (Class IV Soil Evaluator) (this state no longer performs a literal perc test)

RIDEM's Office of Water Resources is the statewide OWTS permitting authority. First check local ordinances and ask the municipal building or planning office whether stricter municipal review applies. Hire a Class IV Soil Evaluator. RIDEM does not automatically attend, but the Director may require witnessing and must notify the applicant within 10 business days and schedule within 15 business days when attendance is required. Complete the site-suitability and design work within the applicable license scopes, then submit the application and fee to RIDEM. RIDEM estimates about three weeks for new construction or alteration review and one to two weeks for repairs, not statutory deadlines. After licensed installation and RIDEM field inspection, RIDEM issues a Certificate of Conformance that the local building official needs before any required Certificate of Occupancy.

The Rhode Island Cesspool Act of 2007 is a separate legacy-system phaseout program, not part of a new-construction soil evaluation, and a cesspool is not a current OWTS design option. Covered cesspools within 200 feet of specified coastal features or public drinking-water sources had to be replaced by January 1, 2014, so remaining covered cesspools are in violation. The statute has limited exemptions tied to qualifying municipal sewer projects and municipal ordinances using a risk-based alternative phaseout schedule. Those legacy exemptions do not replace the soil-evaluation and RIDEM permit path for a new system.

RIDEM charges $150 per system for a soil evaluation, $100 for an OWTS suitability determination, $100 for a wet-season determination, and $150 for new construction or alteration of a single-family residence. These are separate categories and may not all apply; repairs and commercial projects use other fees. Confirm the needed applications and current total with RIDEM or the submitting professional. One operator, Foster Survey Company, published Bronze at $1,600 with the customer supplying the $150 fee and backhoe, Silver at $1,750 including the fee but not the backhoe, and Gold at $5,000 including backhoe service. Foster is the only cited operator, so these tiers are not a statewide average or market range. Get multiple quotes and compare excavation and fee responsibility.

When Rhode Island uses wet-season direct observation to establish seasonal high groundwater, observations must occur from January 1 through April 1. The first reading may be taken no sooner than 48 hours after excavation, and at least three observations must be spaced at least five days apart before Director verification. Not every soil evaluation automatically uses this method or waits for RIDEM staff; witnessing test holes is discretionary. Ask the evaluator whether the site is likely to need wet-season observation. RIDEM's roughly three-week new-work estimate and one-to-two-week repair estimate are planning guidance, not guaranteed deadlines or full project timelines.

Rhode Island uses a RIDEM-licensed Class IV Soil Evaluator for soil-profile and groundwater-table work. A Class IV candidate must pass written and field examinations, earning at least 70 percent on the written portion before taking the field exam, and OWTS licenses expire every three years. Designers have separate scopes: Class I covers documented residential repairs, Class II adds limited new construction and requires Professional Land Surveyor registration, and Class III may design any OWTS through reciprocity for a licensed Civil or Environmental Professional Engineer. More than one professional may contribute, but each must identify the sections prepared. RIDEM's licensing page links a roster PDF from its Class IV entry; confirm current Class IV status directly with RIDEM rather than relying only on the PDF's organization.

RIDEM Office of Water Resources OWTS Licensing · Verify a license