Storm Drainage
Storm drains, catch basins, and yard drainage that won't move water.
- Clogged grates and catch basins
- Standing water and grading issues
- French drain and daylight outlet checks
Lift Stations
Sewage lift and grinder pump stations — alarms, floats, and control panels.
- Alarm / high-level diagnosis
- Pump, float, and check valve testing
- Safe breaker and panel checks
Water Supply
Building water pressure, main lines, pressure tanks, and backflow preventers.
- Whole-building pressure loss
- Main line and PRV checks
- Leak signs and valve audits
Fire Suppression
Sprinkler and suppression systems — impairments, leaks, and inspections.
- Impairment procedure (tag-out + AHJ)
- Active leak and damage response
- NFPA 25 inspection cadence
Sewer & Septic
Sewer backups, main line vs branch clogs, and cleanout checks.
- Multiple-fixture backup triage
- Cleanout level checks
- When to stop using water
Pipe Slope & Gradient
Set the outlet elevation from your run length and inlet invert height.
Total fall
0.52 ft
(6.2 in)
Outlet invert elevation
99.48 ft
trench target depth
Gradient
1.04%
(0.125 in per ft)
Check
Below common minimum — steepen
Measure elevations from the pipe invert (bottom inside of the pipe), not the top. Too little slope clogs; too much (over ~3%) makes liquids outrun solids in sewer lines. Always confirm minimum slopes with your local code office.
Pipe Size & Flow Capacity Chart
Approximate full-flow gravity capacity at a 1% slope (smooth-wall pipe).
| Size | Typical site use | Common materials | Full flow (GPM) |
|---|---|---|---|
| 1 1/2" | Fixture drains, AC condensate | PVC, CPVC, copper | ~5 |
| 2" | Small fixture branches, area drains | PVC, ABS, CPVC | ~15 |
| 3" | Toilet branches, small floor drains | PVC, ABS, cast iron | ~40 |
| 4" | Building drains, sewer laterals, downspouts | PVC, ABS, cast iron | ~85 |
| 6" | Storm mains, small sewer mains | PVC, HDPE, concrete | ~250 |
| 8" | Storm / sewer mains, fire lines | PVC C900, HDPE, RCP, ductile iron | ~540 |
| 10" | Culverts, large storm mains | RCP, HDPE, PVC | ~980 |
| 12" | Culverts, trunk storm lines | RCP, HDPE, CMP | ~1,600 |
Halve the slope and capacity drops about 30%. Sewer lines also carry a max — over ~3% slope liquids outrun solids.
Pipe Materials Guide
Match material to job — soil, load, temperature, and code.
PVC (Sch. 40 / DWV)
Building drains, laterals, storm lines
Cheap, smooth (low friction), glue-jointed. Brittle in cold and UV-degrades above ground.
CPVC
Hot and cold potable water
Handles hot water where PVC can't. Check pressure rating at temperature.
ABS
Residential DWV, exterior drain lines
Handles cold better than PVC; one-step solvent cement; can sun-fade.
HDPE (corrugated / smooth)
Storm drainage, culverts, directionally drilled lines
Flexible, fusion-welded joints, great under settling ground. Needs proper bedding.
Ductile iron
Water mains, fire lines, force mains
High pressure and impact strength; the standard for municipal supply and hydrant feeds.
Reinforced concrete (RCP)
Storm sewers, large culverts, heavy traffic loads
Handles big diameters and live loads; joints need gaskets/mortar, heavy to set.
Galvanized / corrugated metal
Driveway culverts, ditch crossings
Strong and cheap; rusts in acidic or salty soils — check coating (polymer/asphalt).
Site and utility work carries extra hazards: confined spaces (never enter a wet well), sewage exposure, and fire-system code requirements. When a wizard says call a pro — for lift stations, mains, and fire suppression especially — it means it.
