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Ground Water Rule

Florida's public water systems (PWSs) that use ground water will have to comply with the Ground Water Rule (GWR) beginning December 1, 2009. The Ground Water Rule (GWR) was adopted and incorporated by reference into Rule 62-550.828, F.A.C., effective December 30, 2011.

Does the GWR Apply to my System?

The GWR applies to all PWSs that use ground water except for those that combine all of their ground water with surface water, including ground water under the direct influence of surface water, prior to treatment of the surface water.  For the purposes of the GWR, "ground water system" (GWS) means any PWS meeting the  above criteria, including consecutive systems receiving ground water from a wholesale system.

What Is the GWR?

The primary goal of the GWR is to provide increased protection against microbial pathogens, specifically bacterial and viral pathogens.

The basic requirements of the GWR include the following:

• Sanitary surveys,

• Ground water source microbial monitoring,

• Treatment technique requirements, and

• Public notification.

Sanitary surveys are primarily the responsibility of the FDEP, while GWSs are responsible for the other three requirements.

What Are the Ground Water Source Microbial Monitoring Requirements?

Triggered source water monitoring is used to determine if fecal contamination is present in a ground water source/well.  A GWS must conduct triggered source water monitoring if:

• The GWS does not provide FDEP-approved four-log virus treatment  for each ground water source/well; and

• The GWS is notified that a routine distribution system sample is total-coliform-positive (TC+).

  • Exceptions to the triggered source water monitoring requirements: a TC+ routine distribution sample is considered directly related to distribution system conditions, and the GWS is not required to conduct triggered source water monitoring under §141.402(a), if all the following Department criteria are met:

    • The TC+ routine distribution sample is FI-negative;

    • The GWS has no uncorrected significant deficiency at its well(s);

    • The GWS has no uncorrected assessment source water monitoring violation; and

    • All the GWS's well samples are FI-negative dating back to, and including, all those well samples taken during the most recent month or quarter when the GWS took all its required assessment raw water samples.

 When conducting triggered source water monitoring:

• The GWS must collect at least one source water sample for each day one or more TC+ routine distribution system samples were collected by a GWS from each well pumped on the day of the TC+ sample(s) was (were) collected.

• These "initial" triggered source water samples must be collected within 24 hours of notification of the TC+ routine distribution system sample (s) at a location prior to any treatment

• The samples must be analyzed for one of the following three fecal indicators: E. coli, enterococci, or coliphage.

If an "initial" triggered source water sample is fecal-indicator-positive (FI+):

• The GWS must collect five additional source water samples from the same source/well within 24 hours of being notified of the FI+ sample. 

• These "additional" triggered source water samples must be analyzed for one of the three fecal indicators above.  (The "additional" samples may be analyzed for a different fecal indicator than that used for the "initial" sample.) 

• If any one of the five "additional" triggered source water samples is FI+, the GWS must implement corrective action.

Consecutive GWS that has a TC+ routine distribution system sample:

• Must notify its wholesale GWS(s) within 24 hours of being notified of the TC+ sample. 

• The wholesale GWS(s) must conduct, within 24 hours of being notified by the consecutive GWS, triggered source water monitoring unless the wholesale GWS provides FDEP-approved four-log virus treatment for each ground water source/well serving the consecutive GWS.

Assessment source water monitoring is source water monitoring that is in addition to triggered source water monitoring and that also is used to determine if fecal contamination is present in a ground water source/well.  For the purposes of the GWR, the raw water monitoring currently required in Rule 62-550.518, F.A.C., is considered assessment source water monitoring.

 If a raw/assessment source water sample is FI+:

• The GWS may, instead of immediately implementing corrective action, take five "additional" raw/assessment source water samples from the same source/well within 24 hours of being notified of the FI+ sample. 

• If any one of the five "additional" raw/assessment source water samples is FI+, the GWS shall implement corrective action in accordance with Rule 62-555.315(6)(f), F.A.C., and the GWR.

A GWS may use a triggered source water sample to meet the assessment source water monitoring requirements in Rule 62-550.518, F.A.C.  Also, a GWS may use an assessment source water sample collected under Rule 62-550.518, F.A.C., to meet triggered source water monitoring requirements if the assessment source water sample was collected on the same day the TC+ routine distribution system was collected or on any day thereafter up until 24 hours after notification of the TC+ sample.

Ways to Reduce the Burden of Triggered or Assessment Source Water Monitoring [.doc 30 kb]

What Are the Treatment Technique Requirements?

Corrective action is required when:

• An "additional" triggered or assessment source water sample is FI+ or,

• A significant deficiency is identified by the FDEP during an inspection.  Significant deficiencies include defects in design, operation, or maintenance and include a source, treatment, storage, or distribution facility failure or malfunction that could cause contamination of water.

GWSs must consult with the FDEP regarding the appropriate corrective action within 30 days of receiving written notice from the FDEP of a significant deficiency or written notice from a laboratory that an additional triggered or assessment source water sample was found to be FI+.  Within 120 days of receiving such a written notice, GWSs must either have completed corrective action or be in compliance with an FDEP-approved corrective action plan and schedule.  Also, if the FDEP specifies any interim measures for protection of public health pending completion of corrective action, GWSs must comply with those interim measures.

Corrective action alternatives include the following:

• Correct all significant deficiencies.

• Provide an alternate source of water.

• Eliminate the source of contamination.

• Provide 4-log virus treatment before or at the first customer for the ground water source.

Compliance monitoring:

• Must be conducted by GWSs that either provide four-log virus treatment as a corrective action or provide four-log virus treatment instead of conducting triggered source water monitoring. 

• GWSs using chemical disinfection to achieve four-log virus treatment and serving more than 3,300 people must continuously monitor the residual disinfectant concentration at the end of the disinfectant contact zone, which must be before or at the first customer.  Additionally, pH and temperature must be checked daily at or before the first customer during the period of peak flow.

• GWSs using chemical disinfection to achieve four-log virus treatment and serving 3,300 or fewer people must take a daily grab sample at the end of the disinfectant contact zone during peak flow.  Additionally, pH and temperature must be checked daily at or before the first customer during the period of peak flow.

What Are the Public Notification Requirements?

The following table outlines the various situations or violations for which notification is required and the corresponding types of notification that are required.

Drinking Water Contacts:   Field Compliance -- In House Compliance -- Permitting

Central District

Drinking Water Section

3319 Maguire Blvd., Suite 232

Orlando, Florida 32803-3767

Compliance Fax: 407-897-4189

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