300-Foot Well Drilling Cost

Why 300 feet is the bedrock bracket

At 300 feet, the surface aquifers are almost always behind you. The water you are reaching is in fractures within crystalline or sedimentary rock, or in deeper confined sand-and-gravel aquifers below a confining clay layer. Either way, the per-foot drilling rate has stepped up because the bit is working harder, the rig is configured for hard ground, and the drilling time per foot has roughly tripled compared to a shallow sand well.

The 300-foot bracket is where two cost dynamics shift visibly. First, the drilling rate moves up: most drillers price a third tier above 250 feet, often $5 to $8 more per foot than the first 100 feet, to absorb the slower penetration and bit wear. Second, the pump cost moves up because lifting water 300 feet requires more horsepower and more drop pipe. The combination means a 300-foot well does not cost 50 percent more than a 200-foot well in the same geology; it usually costs 60 to 80 percent more because both line items have stepped.

The compensating advantage is water quality. Bedrock-aquifer water at 300 feet is usually older, slower-moving and better-protected from surface contamination than alluvial water at 100 feet. The lab results on a 300-foot bedrock well typically come back clean for coliform and nitrate on the first try, and the maintenance schedule is gentler over the well's 30 to 50 year life.

Cost breakdown line by line for a representative bid

Take a 300-foot well in central Pennsylvania, drilled through 50 feet of clay-over-shale into 250 feet of fractured Marcellus-zone shale and sandstone. Six-inch steel casing is set 50 feet to seal off the soft upper material. The remaining 250 feet is open bore through the bedrock. A 1.5 HP submersible pump is set at 280 feet on galvanized drop pipe (galvanized at this depth resists the longer column weight better than plastic). A 44-gallon pressure tank goes in the basement.

Line items at 2026 rates. Mobilisation $900. Drilling 50 feet clay-and-shale at $40 per foot ($2,000). Drilling 250 feet sedimentary-rock bedrock at $48 per foot ($12,000). Six-inch steel casing 50 feet at $16 per foot ($800). Grouting 30 feet, $500. Well cap with pitless adapter, $250. Development 5 hours, $600. Submersible pump 1.5 HP with control box, $2,000. Drop pipe (galvanized) and electrical 280 feet, $1,400. Pressure tank 44 gallon, $750. Trench from well to house 200 feet, $800. Permit and water test $300. Subtotal: $22,300. With 10 percent contingency, $24,530. That is a typical upper-middle bid for central-PA bedrock in 2026.

The drilling component ($14,000) is 63 percent of the total. Casing, grouting, pump, drop pipe and tank ($5,200) is another 23 percent. Everything else is 14 percent. The proportions are slightly skewed toward drilling vs the 200-foot bracket (where drilling was 60 percent) because the bedrock per-foot premium dominates.

Regions where 300 feet is the typical depth

Mid-Atlantic bedrock zone (PA, NY, VA, MD, DE). The Piedmont and Valley-and-Ridge geological provinces typically produce residential water from fractured sedimentary or metamorphic bedrock at 200 to 400 feet. The 300-foot median is well-documented in Pennsylvania Geological Survey records and similar databases for the other states.

Southern Appalachians (TN, NC mountains, GA mountains, AL highlands). Granite-gneiss and metamorphic-schist bedrock with fracture-flow aquifers. The 250 to 350 foot range captures the bulk of residential drilling. Yields are unpredictable: a 320-foot well producing 8 gpm sits next door to a 310-foot well producing 1 gpm. Hydrofracturing is widely used here as the standard low-yield remedy.

Texas Hill Country (Edwards-Trinity aquifer). The Edwards aquifer underlies the limestone of central Texas at 200 to 400 feet. Karst features (cavities, sinkholes) make the drilling rate hard to predict: some bores hit cavities and "drop" several feet of free fall, requiring reaming and recovery time that the bid did not anticipate. Per-foot rates here run $40 to $55 even in nominally "soft" limestone because of this drilling uncertainty.

Pacific Northwest basalt (parts of WA, OR, ID). Columbia River basalt aquifers sit at 200 to 600 feet. Basalt is hard-rock drilling, often DTH-hammer territory, with per-foot rates similar to New England granite. A 300-foot well in basalt runs at the upper end of the cost range.

Why the rig type matters at this depth

Two rig types dominate 300-foot residential drilling, and the choice affects both the bid and the well's performance.

Air-rotary rig with down-the-hole (DTH) hammer. Most common for hard-rock drilling at 300 feet. The DTH hammer is essentially a pneumatic jackhammer at the bottom of the drill string, fed by compressed air from a large compressor at the surface. Penetration in hard rock can be 20 to 40 feet per hour, much faster than rotary alone. The downside: the compressor uses 100 to 200 gallons of diesel per day, the noise is significant (often 95 to 105 dB at the rig), and the dust-collection requirements get strict in residential neighbourhoods. Drillers using DTH typically price slightly higher per foot to cover fuel and dust-control overheads.

Mud-rotary rig. The traditional choice for soft to medium-hard ground. A tricone bit chews into the rock; drilling mud (a clay-water mix) lifts the cuttings out of the bore and lubricates the bit. In sedimentary rock at 300 feet, mud-rotary is often as fast as air-rotary and cheaper to run. The downside is that mud invasion of the producing fracture zone can reduce initial yield; development time has to be longer to clear the mud out.

On a 300-foot bid, ask which rig type the driller is bringing. If two competing bids use different rigs, the lower per-foot rate on the mud-rotary bid may be offset by longer development time and lower initial yield. The DTH bid may produce better initial water at higher per-foot cost.

Pump and drop pipe at 300 feet

The 300-foot pump decision is more consequential than the 200-foot decision. The pump motor has to lift more water against more head pressure, the drop pipe has to support its own weight plus the column of water inside it, and the electrical run is longer with more voltage drop. Each of those margins gets tighter at 300 feet.

Drop pipe material. At 200 feet, schedule-80 PVC drop pipe is standard and inexpensive. At 300 feet, the column weight (water plus pipe) starts to exceed PVC's tensile rating in some setups. Many drillers spec galvanized steel or polyethylene rated for deep service at this depth. Galvanized adds about $4 per foot over PVC; the durability margin is worth it.

Pump HP. A 1 HP pump can technically lift water from 300 feet at low flow rates, but most installers spec 1.5 HP at this depth to leave headroom for the household's peak demand and for moderate static-level decline over the years. A 1.5 HP pump costs $250 to $400 more than a 1 HP pump and consumes 15 percent more electricity per gallon pumped. The math usually favours the bigger pump.

Electrical service. Pump wiring run from a 220V breaker through 280 feet of submersible cable (encased in the drop pipe) must be sized to avoid voltage drop at start-up. Most installers use 12 AWG at 200 feet and 10 AWG at 300 feet. The wire is part of the standard pump-install package but worth confirming on the bid.

See pump installation costs for the full pump-type comparison.

Hydrofracturing at 300 feet

Hydrofracturing is more common at this depth than at any shallower depth, because bedrock-fracture wells in the 250 to 400 foot range are exactly where hydrofracture works best. The process pumps water into the well at high pressure (1,500 to 3,000 psi) using inflatable packers to isolate the producing zone; the pressure widens existing fractures and opens new ones. The 70 to 80 percent success rate cited by NGWA applies most squarely to wells in this depth bracket.

Cost: $1,500 to $4,500 for a single zone, $2,500 to $6,000 if multiple zones are fracked. Compare that to deepening: an additional 100 feet at $48 per foot is $4,800, with no guarantee of better yield in a hard-rock well where fracture systems are unpredictable. The hydrofracture math almost always wins for 300-foot bedrock wells with low initial yield. See well hydrofracturing for the full process and success-rate breakdown.

Cross-references and adjacent depths

For the per-foot rate breakdown, well drilling cost per foot 2026. For the shallower bracket, 200-foot well drilling cost. Next depth up, 400-foot well drilling cost. For state pricing, Texas (Hill Country) is the most-common 300-foot bracket; cost by state for the rest. For the bedrock-drilling premium that dominates this depth, bedrock well drilling cost.