Home Water Supply Basic Facts a Homeowner Needs to Know 46% of NH Population Served by Private Wells 520,000 People Served by 250,000 Wells Basic Facts a Homeowner Needs to Know 1) What Type of Well? 2) How Much Water? 3) Is the Water Safe to Drink?

Well Database No. Records in Well Database 124,500 Wells Constructed Annually in NH 2,000 to 6,000 Wells Constructed in 2015 2,000+ Well Type % Total Wells 1) Drilled in Bedrock 95 2) Constructed in Sand and Gravel 4 3) Dug Wells Constructed by Excavation < 1 Median Depth (ft) Median Yield (gpm) Deepest Well (ft) Bedrock Wells 320 8 2,500 Windham Wells 405 10 Deepest Well Windham Deepest Gravel Well Cornish 100 gpm No. Wells w/Depths Ranging from 1,000 to 2,500 ft 1,600+ Windham Well Depths from 1,000 to 2,500 ft 221

Fractured Bedrock Aquifer Median Depth to Bedrock is 19 feet Minimum Casing 10 feet into Competent Bedrock Age of NH Rocks 470 Ma Ordovician to 175 Ma Jurassic Windham Data Berwick Formation Age – Silurian Period about 425 MA Median Depth to bedrock = 8 feet

Bedrock Well Construction

Air Rotary Drilling New Rotary Rig $680,000 Water & Pipe Truck $210,000 Drill Rods and Hammers $75,000 Pickup Truck $48,000 Kabota $30,000 On-Site Equip $1.1 to 1.2 Million

Cable Tool Drilling Robert Carr Water Wells Commonly called “Pounder” About 20 Cable Tool Drillers Licensed in NH Drill Rates 20 to 30 feet per day

Setting Casing Minimum Depth - 20 feet 10 feet into Competent Bedrock Driveshoe Required Sealed to Bedrock Competent Bedrock – Structurally sound, w/ min fractures, joints, partings, and faults and Chemical or Physical weathering. 10 feet into Competent Bedrock

Glacial Stratified Drift Aquifer Gravel Wells Pleistocene Epoch 1,600,000 years to 10,000 years

Dug Wells

Lincoln Well Depth 522 ft Yield 40 gpm

Compressed Air Test

No State Requirement for Minimum Well Yield Recommended Minimum Capacity 600 Gallons within a 2 Hour Period at Least Once Per Day Equal to: 5 Gallons Per Minute for 2 Hours

Minimum Capacity Table Supply 600 Gallons in 2 Hours Sustained Well Yield [gpm] Required Well Depth [ft] 0.5 400 1 360 1.5 320 2 280 2.5 240 3 200 3.5 160 4 120 4.5 80 5 ---

Well Yields for Domestic Bedrock Wells Yield Range [gpm] Statewide Percent of Total Town of Windham Greater than 5 60% 62% Between 2.1 and 5 30% 19% Between 0.5 and 2 9% 14% Less than 0.5 1% 5%

Hydro-Fracturing 500 to 2,000 psi 50 gpm pump 1,500 to 2,000 gal pumped

Hydraulic Pressure Median Increase 3.5 gpm Number of Wells 5,675 5% Wells

Water Bearing Fracture After Development Before Frac <1/2 GPM w/ 400’ static After Frac 6 gpm at 125’ fracture Photo taken during pumping test

Median Increases in Yield following Hydrofracturing – February 2001 Based on 1,089 wells

Wellhead Protection 8 to 12 Inches Above Ground Sealed Cover Screened Vent Electrical Conduit Secured to Cover Submersible Pump Ground Wire Bonded to Casing

Wire Connections & Grounding Submersible pump motors grounded and bonded to well casings. Wire connections must be water tight. Exception:Grounding conductor Wire nuts prohibited

Common Non-Compliant Cover

Electrical Conduit Not Secured

Busted!

Artesian Well w/ Caulking Seal? No Electrical Conduit?

Duct Tape!

Dug Wells Minimum 18 Inches Above Ground Surface Dug Well with Access Plug

No Cover

Gruesome Discovery

Well Pits

Drinking Water and Groundwater Bureau at 271-3209 Well Information Well Construction Details on the Web http://des.nh.gov Look for OneStop Data and Information Or Call NH Geological Survey at 271-1976 or Drinking Water and Groundwater Bureau at 271-3209