Also in: Disaster Response and Recovery
Chlorine Demand and Dose for a Target Residual
Chlorine the water consumes, and the dose needed to hold a target residual.
Example
You enter
- Applied chlorine (mg/L) 3
- Measured residual (mg/L) 0.8
- Target residual (mg/L) 1
You get
- Chlorine demand 2.20 mg/L
- Dose for target 3.20 mg/L
- High demand No
Checked against published worked examples from: California DPH / RCAC.
Details, formula, and sources
ScopeThe chlorine consumed by the water (applied minus the measured residual) and the dose to hold a target residual (demand + target). A high or rising demand points to ammonia or organics - check the breakpoint curve. Standard Methods 4500-Cl / AWWA M14; the state primacy agency sets the compliance residual and method.
Formula or tabledemand = applied - measured_residual; dose_for_target = demand + target_residual. A high demand (flagged above 4 mg/L) suggests ammonia / organics - check the breakpoint curve.
Source and editionStandard Methods 4500-Cl / AWWA M14 (by name); applied-minus-residual mass balance, no edition cycle.
Free accessThe mass balance is public; the compliance residual, contact time, and method are set by the state primacy agency.
What governsEstimate. Operator of record and primacy agency govern.
API field namesapplied_mg_l, measured_residual_mg_l, target_residual_mg_l, demand_mg_l, dose_for_target_mg_l, high_demand
- Mass balance demand is the chlorine consumed: applied minus the measured residual after the contact periodStandard Methods 4500-Cl
- Breakpoint a high or rising demand points to ammonia / organics; free vs combined chlorine matters - check the breakpointAWWA M14
- Primacy agency the state primacy agency sets the compliance residual and the approved methodstate primacy agency