Connecticut Well Driller Compliance Reference

Required Forms by Situation

• Before Drilling (Water-Supply Wells): State Drill Permit ($5 to DCP) + Local Health Permit (fee varies by town)
• After Completion (All Wells): Well Construction Report (online via eLicense within 60 days to DCP, DEEP, local health, owner)
• Non-Water-Supply Wells: Same completion report requirements (includes site map)
• Abandonment/Sealing: Completion report marked "Abandoned" (within 60 days)
• License Application: Form OCC-WELLDRL-APP (via eLicense portal)

Connecticut requires individual driller registration (not company licenses) per Conn. Gen. Stat. Chapter 482.

License Types & Fees

Experience Requirements

Exam Information

Continuing Education

Well Log Requirements

Every completion report must include:

• Owner name and address
• Well location (street address + GPS coordinates if available)
• Total depth and geology (lithology, layer thicknesses)
• Water-bearing zones encountered
• Casing size, material (steel/PVC), and length
• Grouting/sealing information (depth, material)
• Static water level
• Pump test data (if conducted)
• Local health director signature (confirming well conforms to code)

Casing Requirements

• Materials: New steel primary casing, free of pits and breaks, with minimum weights and wall thicknesses per Table 1 of Regs §25-128-43. Schedule 40 PVC (ASTM D-1785) is allowed only for liner pipe and screens.
• Purpose: Prevent wall collapse and seal off surface drainage
• Height: Casing must extend at least 6 inches above the land surface (Regs §25-128-43(b))
• Length: Drilled wells need at least 20 ft of casing, extending at least 5 ft into bedrock (Regs §25-128-44)
• Cap: Sanitary sealed well cap required (watertight, prevents vermin/runoff intrusion)
• Screens: Slotted casing permitted in unconsolidated aquifers

Annular Seal (Grouting)

• Material: Low-permeability cement-bentonite slurry or neat cement
• Purpose: Prevent contaminants entering aquifer through annular space
• Depth: Grout fills the annular space from the frost level to the bottom of the casing; where special conditions exist, from the frost level to at least 10 ft below the land surface (Regs §25-128-43(b))
• Definition: "At least as impermeable as soil formation" per Regs §25-128-36

Setback Requirements (RCSA §19-13-B51d)

Disinfection (Mandatory)

Connecticut requires disinfection of all newly constructed wells for human consumption (unless owner signs written waiver). Per Regs §25-128-36, disinfection means "inactivating organisms through use of an accepted chlorine solution or other disinfection procedure approved by the Commissioner."

• Standard method: Shock chlorination (strong bleach solution)
• Contact all well surfaces (bailer or circulation)
• Flush until clear before sampling
• Document disinfection procedure in completion report

Surface Completion

• Ground must slope away from wellhead to divert runoff
• Maintain clear zone around wellhead (10 ft minimum recommended)
• If well is in pit: pit must stay dry and sealed (though above-ground preferred)
• Wellhead protection in flood-prone areas: elevate 3-5 ft above highest flood mark

Water-Supply Wells (Residential/Potable)

Non-Water-Supply Wells

Test wells, monitoring wells, seismic wells, or geothermal wells not intended for potable use do NOT require state/local permits under §25-130. However:

• Check with local zoning or DEEP if in protected area
• Must still file completion report within 60 days (to DCP, DEEP, local health)
• Requires W-3/W-4 license (Limited Non-Water-Supply Driller)

High-Capacity Wells

Wells in one system whose combined maximum withdrawal exceeds 50,000 gallons in any 24 hours may require a DEEP Water Diversion Permit. Contact CT DEEP's Water Permitting & Enforcement Division (860-424-3705) for large municipal/industrial supply wells.

Special Well Types

• Geothermal (Closed-Loop): Requires W-7/W-8 license (geothermal driller); no separate geothermal permit beyond driller license
• Geothermal (Direct-Exchange/DX): Requires W-9/W-10 license (copper-loop wells)
• Casing Extension Only: Requires W-5/W-6 license (contractor must also hold CT plumbing license)

Common Drilling Challenges

• Hard Crystalline Rock: Most upland areas (slow drilling, noisy, sparse fractures = low yields)
• Running Sand/Collapsing Holes: Intermixed till layers require casing to prevent collapse
• Karst Voids: Carbonate zones may have unpredictable caverns or boulders
• Artesian Flow: Confined sand aquifers (especially in river valleys) may cause flowing wells; have valves ready
• Water Quality: Expect iron-bacteria, high minerals (sulfate/hardness in carbonate), manganese in drift, arsenic in bedrock

Seasonal Considerations

• Winter Frost: Ground can freeze 3-4 ft deep; remove snow, insulate pumps, drain lines when not pumping
• Spring Flooding: Valley and coastal areas may flood; site wells above floodplain (3-5 ft elevation minimum)
• Water Table Fluctuations: Upland wells see seasonal swings; test static levels and plan for drawdown
• Access Issues: Muddy or snowy conditions in shoulder seasons limit rig access

Arsenic Testing

Connecticut law now requires testing all new wells for arsenic. While no special casing depth is mandated, advise clients to:

• Test before using well water for drinking
• Install treatment systems (RO or adsorptive media) if arsenic exceeds 0.010 mg/L EPA MCL
• Consider casing deeper into low-arsenic strata in known hotspot areas

Wellhead Protection Zones

Public water supply wells in Connecticut have delineated protection zones. Regulations (RCSA 19-13-B51d) require a 200-ft standoff zone around public wells >50 gpm. Many towns implement wellhead protection ordinances overlaying larger "Zones of Contribution."

Before drilling near community wells, check with local health for overlay restrictions (e.g., prohibited hazardous materials within protection area).

Contaminated Sites

Drilling near known hazardous sites (landfills, Superfund, dry cleaners, industrial areas) may require special approval. Consult DEEP's contaminated site maps or local health if a planned well is near an old waste site. Additional testing or non-aqueous phase liquid (NAPL) restrictions may apply.

Regulatory References

• Conn. Gen. Stat. Chapter 482 – Connecticut Well Drilling Code (§§25-126 through 25-136)
• Regs. Conn. State Agencies §25-128-36 – Definitions (casing, grout, disinfection)
• Regs. §19-13-B51(d) – Public Health Code well location and setbacks
• CT DCP Well Drilling Page – Forms, license applications, scope of work