Water Management, Underground Tank & Boring Guide

Haripur homes depend on bores, tankers and intermittent supply, so an underground reservoir is your insurance. As a rule: 4–6 persons ≈ 2,500 gallons. Adjust the numbers below.

A leaking tank fails twice: it loses water, and — worse — groundwater, septic seepage and soil bacteria leak in and contaminate what your family drinks. Waterproof it from both sides.

• Site it uphill and ≥ 30 ft (10 m) from any septic tank, soak pit or drain; the tank sits in clean, firm soil above the seasonal water table where possible.
• Raft and walls in 1:1.5:3 RCC with a waterproofing admixture; wall at least 9 in thick, bars double-layer, cover ≥ 2 in. Concrete must be well vibrated — honeycombing is a leak path.
• Pour the raft and walls with as few joints as possible; at every construction joint put a PVC water-stop (⑤).
• Inside: 2 coats crystalline waterproofing slurry, then a food-grade (potable-water) epoxy or tile with waterproof grout. Do not use ordinary paint or industrial bitumen inside.
• Outside: 2 coats of bitumen or a bituminous membrane, protected by a 4.5 in brick or polystyrene board before back-filling so stones don't puncture it.
• Floor slopes 1:50 to a sump so the tank can be cleaned fully; roof slab has a raised manhole kerb (≥ 6 in) with a lockable lid, and a vent with insect mesh.
• Overflow pipe must discharge to a drain through a visible air gap — never into a soak pit or sewer line.
• Leak test: fill completely, mark the level and wait 7 days. A drop beyond evaporation means a leak — repair before backfilling and before using. Chlorinate and flush before first use.

• Ask 3–4 neighbours for their bore depth, water level and quality before you drill — in Hazara's mixed hill and plain soils, depth varies a lot between plots.
• Keep the bore ≥ 50 ft (15 m) — ideally more, and up-slope — from septic tanks, soak pits and animal sheds.
• Use PVC (or MS) casing, a gravel pack around the screen, and a sanitary seal: grout the top 20 ft around the casing with cement so surface water can't run down.
• Build a 3 ft × 3 ft concrete platform around the bore head sloping away, and a lockable cap.
• Get the water tested (TDS, hardness, arsenic, bacteria) at a certified lab (e.g. PCRWR / public-health lab) before drinking it; add filtration if needed.
• Pump into the underground tank first, then lift to the roof tank — this reduces running hours and gives you a buffer.

Haripur gets short, intense monsoon storms, and paved plots send all of that water to the street while local groundwater tables fall. A soak pit sends roof water back underground.

• Drain roofs with 3–4 in downpipes (one per ~500 sq ft); give the roof a 1:100 slope to outlets and keep gutters clear.
• Always pass water through a silt chamber with a mesh/charcoal filter so the pit's gravel doesn't clog.
• Pit: 4 ft diameter × 8–10 ft deep, brick-lined with open joints (or perforated rings), filled with 1–2 in gravel and broken brick, covered with a perforated slab.
• Place ≥ 10 ft from foundations (saturated soil under a footing is dangerous), ≥ 30 ft from septic tanks and bores, and never connect to the underground drinking-water tank.
• On sloping hill plots, check with your engineer first — don't soak water above a retaining wall or slope.