Surface Water Treatment Rule | Drinking Water Compliance Assistance

The Surface Water Treatment Rules require water systems to filter and disinfect surface water sources. Some water systems are allowed to use disinfection only for surface water sources that meet criteria for water quality and watershed protection.

What to Do If There's an Exceedance for:
Maximum Turbidity Limit 

  • Contact ADEQ as soon as possible, no later than 24 hours after the system learns of the exceedance.
  • Post ADEQ-approved boil water advisory, Tier 1 public notice as directed by ADEQ, within 24 hours.
  • If you believe there is an outbreak of a waterborne illness contact ADEQ and your county’s Health Department immediately.

95 Percent Turbidity Monthly Limit

  • Contact ADEQ as soon as possible, no later than 48 hours after the system learns of the exceedance.
  • Distribute a Tier 2 public notice as soon as possible, within 30 days.
  • If you believe there is an outbreak of a waterborne illness contact ADEQ and your county’s Health Department immediately.

Chlorine Residuals at EPDS Fall Below 0.2 Milligrams per Liter (mg/L)

  • The system must maintain a residual level of 0.2 mg/L or higher within 4 hours. 
  • If the system collects daily samples, increase sample collection to every 4 hours until the residual level reached 0.2 mg/L or higher. 
  • If the residual level is not maintained within 4 hours, distribute a Tier 2 public notice as soon as possible, within 30 days. 
  • If you believe there is an outbreak of a waterborne illness, contact ADEQ and your county’s health department immediately.

Chlorine Residuals in Distribution are Undetected for Two Consecutive Months

  • Distribute a Tier 2 public notice as soon as possible, within 30 days. 
  • If you believe there is an outbreak of a waterborne illness, contact ADEQ and your county’s Health Department immediately.