All large public water systems shall monitor water quality parameters in addition to lead and copper in accordance with this rule. All small and medium public water systems that exceed the lead or copper action level shall monitor water quality parameters in addition to lead and copper in accordance with this rule. For performing the analyses of water quality parameters set forth in this rule, laboratories are exempt from the requirements of rule 3745-89-02 of the Administrative Code. The requirements of this rule are summarized in the table at the end of this rule.
System size (number of people served) | Number of sites for water quality parameters |
> 100,000 | 25 |
10,001 - 100,000 | 10 |
3,301 - 10,000 | 3 |
501 - 3,300 | 2 |
101 - 500 | 1 |
< 101 | 1 |
Any small or medium public water system shall conduct such monitoring during each six-month period specified in this paragraph. For any such small or medium public water system that is subject to a reduced monitoring frequency pursuant to paragraph (D)(4) of rule 3745-81-86 of the Administrative Code, at the time of the action level exceedance, the start of the applicable six-month period under this paragraph shall coincide with the start of the applicable monitoring period under paragraph (D)(4) of rule 3745-81-86 of the Administrative Code. Compliance with director-designated optimal water quality parameter values shall be determined as specified under paragraph (G) of rule 3745-81-82 of the Administrative Code.
Upon the determination of an action level exceedance, any public water system that is subject to a reduced monitoring frequency pursuant to paragraph (D)(4) of rule 3745-81-86 of the Administrative Code shall report applicable water quality parameters in accordance with this rule within thirty days or by the end of the water quality parameter monitoring period, whichever is sooner.
System size (number of people served) | Reduced number of sites for water quality parameters |
> 100,000 | 10 |
10,001 - 100,000 | 7 |
3,301 - 10,000 | 3 |
501 - 3,300 | 2 |
101 - 500 | 1 |
< 101 | 1 |
Summary of Monitoring Requirements for Water Quality Parameters 1
Monitoring Period | Parameters | Location | Frequency |
Initial monitoring. | pH, alkalinity, orthophosphate or silica2, calcium, conductivity, temperature. | Taps and at entry point(s) to distribution system. | Every 6 months. |
After installation of corrosion control. | pH, alkalinity, orthophosphate or silica2, calcium3. | Taps. | Every 6 months. |
pH, alkalinity dosage rate and concentration (if alkalinity adjusted as part of corrosion control), inhibitor dosage rate4 and orthophosphate or silica2. | Entry point(s) to distribution system5. | No less frequently than every two weeks. | |
After director specifies parameter values for optimal corrosion control. | pH, alkalinity, orthophosphate or silica2, calcium3. | Taps. | Every 6 months. |
pH, alkalinity dosage rate and concentration (if alkalinity adjusted as part of corrosion control), inhibitor dosage rate4 and orthophosphate or silica2. | Entry point(s) to distribution system5. | No less frequently than every two weeks. | |
Reduced monitoring. | pH, alkalinity, orthophophate or silica2, calcium3. | Taps. | Every 6 months, annually6 or every 3 years7; reduced number of sites. |
pH, alkalinity dosage rate and concentration (if alkalinity adjusted as part of corrosion control), inhibitor dosage rate4 and orthophosphate or silica2. | Entry point(s) to distribution system5. | No less frequently than every two weeks. |
1 Table is for illustrative purposes; consult the text of this rule for precise regulatory requirements.
2 Orthophosphate shall be measured only when an inhibitor containing a phosphate compound is used. Silica shall be measured only when an inhibitor containing silicate compound is used.
3 Calcium shall be measured only when calcium carbonate stabilization is used as part of corrosion control.
4 Inhibitor dosage rates (orthophosphate or silica) shall be measured only when an inhibitor is used.
5 Ground water systems may limit monitoring to representative locations throughout the public water system.
6 Water systems may reduce frequency of monitoring for water quality parameters at the tap from every six months to annually if the system meets the requirements in paragraph (E)(2) of this rule.
7 Water systems may further reduce the frequency of monitoring for water quality parameters at the tap from annually to once every three years if the system meets the requirements in paragraph (E)(2) or (E)(3) of this rule.
Ohio Admin. Code 3745-81-87
Promulgated Under: 119.03
Statutory Authority: 6109.121, 6109.04
Rule Amplifies: 6109.121, 6109.04
Prior Effective Dates: 09/13/1993, 10/17/2003, 07/24/2009, 02/23/2015, 05/01/2018
Five Year Review (FYR) Dates: 1/31/2018 and 05/01/2023
Promulgated Under: 119.03
Statutory Authority: 6109.121, 6109.04
Rule Amplifies: 6109.04, 6109.121
Prior Effective Dates: 9/13/93, 10/17/03, 7/24/09, 2/23/15