Regulations, Monitoring, Reporting, Safety, and Calculations
Regulatory framework
The Safe Drinking Water Act sets the framework; EPA writes National Primary Drinking Water Regulations; Alabama's primacy program, administered by ADEM, adopts and enforces them and manages operator certification. Know representative standards: nitrate 10 mg/L as N, arsenic 10 µg/L, lead action level 0.015 mg/L and copper 1.3 mg/L at the 90th percentile, TTHM 80 µg/L and HAA5 60 µg/L as locational running annual averages, and the total coliform/E. coli rules with their Level 1 and Level 2 assessments. Turbidity limits follow the surface water treatment rules.
Monitoring and reporting
Follow the approved monitoring schedule and submit monthly operating reports. The Consumer Confidence Report is due to customers by July 1 for the previous calendar year. Public notice is tiered: Tier 1 violations require notice within 24 hours. Keep records for the period your rule specifies, and report sample results honestly and on time.
Safety
Chlorine gas requires a detector, ventilation, and SCBA; approach leaks from upwind. Observe confined space entry permits, atmospheric testing, lockout/tagout, trenching protection, PPE, and traffic control. Chemical handling rules apply: never add water to concentrated acid or caustic, and always add chemical to water.
Calculations to master
Pounds per day = mg/L × MGD × 8.34; dose = lb/day ÷ (MGD × 8.34); detention = volume ÷ flow; percent removal; tank volume = 0.785 × D² × H × 7.48 gallons per cubic foot.
Worked example
A system feeds 1.8 mg/L chlorine at 2.5 MGD: 1.8 × 2.5 × 8.34 = 37.5 lb/day of chlorine.