Operational Evaluation Level Stage 2 D/DBP Rule Compliance Michael W. Deal Compliance Assurance Section Central Office Division of Drinking And Ground Waters

Overview Ohio Administrative Code Goals of OEL Calculation OEL Exceedance OEL Form 5031 Take Home

Ohio Administrative Code OAC (D) (21) OEL calculated for DBPs at all monitoring locations Exceedance of the MCL requires a report OEL report due 90 days following notification Publicly accessible upon request

Goals Primary: to help prevent an MCL through advanced warning of increased DBP Locational Running Annual Averages (LRAA) for quarterly monitoring Secondary: to cause PWSs to address locations or facilities with seasonal DBP issues

Calculation of OEL A = TTHM or HAA5 result for the quarter before the previous quarter B = TTHM or HAA5 result for the previous quarter C = TTHM or HAA5 result for current quarter D = Current Operational Evaluation Level Value

Example Location “X” (DS201) TTHM Results Current Quarter Value (3 rd Qtr 2013) ……………………... ( µg/L ) 2 Previous Quarter Value (2 rd Qtr 2013)……………….....…….61.3 µg/L Quarter Before Previous (1 st Qtr 2013)… ……… µg/L µg/L 4 OEL = 83.6 µg/L

OEL Exceedance Early warning Not a violation No public notice requirement Can be at 1 or more monitoring location(s) TTHM or HAA5

Following an Exceedance 1.Receive call from OEPA to determine scope 2.Receive letter from OEPA with report template 3.Complete OEL report (Form 5031)

45 Total 84% 3 rd Quarter 62% Purchased SW 6 Repeat OEL Exceedances (Since Aug. 2012)

Limited Scope Limited scope OEL report if cause is known High DBP levels result from a certain change in water quality, treatment or distribution

What’s the Point? Begin dealing with DBP issues prior to NOV Investigate areas of concern Make adjustments to lower DBP levels Document investigation on Form 5031

OEL Form 5031

Section 1 – Source Water and Treatment

Noteworthy Changes to Source Water:  Significant algal blooms  Uncharacteristic precipitation events  Alternative well usage  Distinctive change to purchased water Changes to Treatment:  Chemical feed increase or decrease  Chemical product changes Section 1 – Source Water and Treatment

Section 2 – Distribution System Operations

Noteworthy Events or Changes to the Distribution System:  Hydrant flushing  Line breaks  Rerouted flow  Significant demands

Section 3 – Storage Tank Operations

Section 4 – Chlorine Residual Monitoring

Disinfectant residual information;  Average residual can be found on your MOR  Number of distribution samples includes daily samples and samples collected with TC  Number of samples <0.2 mg/L for free or <1.0 mg/L for combined chlorine  Repeated for each month of the quarter

Section 5 – Additional Information

 Additional monitoring information  Plans to comply with the MCL  Corrective actions taken from past OEL exceedances

Take Home Early warning not a violation OEPA will notify of an exceedance Report covers treatment, storage and distribution Failure to submit a report is a violation Goal is to optimize control of DBPs and avoid MCL exceedances

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