Completing an EPA Stage 2 DBPR Operational Evaluation made EASY!

Transcription

1 Completing an EPA Stage 2 DBPR Operational Evaluation made EASY! CA/NV AWWA FALL CONFERENCE October 3, 2013 SMURPH SAYS: You might try READING the GUIDANCE manuals!!

2 5 Key Points to Learn Formula used to determine OEL exceedance Requirements IF the OEL is exceeded Pros/Cons of using the whole 90 days Steps to minimize future OEL exceedances Write a conclusion your regulator will LOVE

3 Cement Hill WTP and Putah South Canal

4 WHAT DOES OEL stand for? The Stage 2 DBPR requires systems to conduct operational evaluations, initiated by the operational evaluation levels (OEL) found in Stage 2 DBPR compliance monitoring, and to submit an operational evaluation report to the State.

5 It s great to be FIRST, at SOME things! U.S. EPA orders Solano Irrigation District to remove chemical from drinking water Release Date: 5/10/2005 Contact Information: Mark Merchant (415) SAN FRANCISCO - The U.S. Environmental Protection Agency recently ordered the Solano Irrigation District to reduce levels of disinfection byproducts from drinking water treated by the district s Gibson Canyon water system. The EPA promulgated new disinfection byproduct regulations in December 1998 to protect public health from potentially harmful byproduct chemicals formed when chlorine reacts with natural organic compounds during the treatment process. This is the first action taken by the EPA against a small water system in California under the agency s disinfection byproduct regulation.

6 Formula to Determine OEL exceedance Formula for Determining if You Have an OEL Exceedance For both TTHM and HAA5 and for each compliance monitoring location, calculate the following: (A + B + (2 * C)) / 4 = D Where: A = TTHM or HAA5 result for the quarter before the previous quarter (mg/l) B = TTHM or HAA5 result for the previous quarter (mg/l) C = TTHM or HAA5 result for the current quarter (mg/l) D = your Operational Evaluation Value (mg/l) If D for TTHM is > mg/l, you have an OEL Exceedance If D for HAA5 is > mg/l, you have an OEL Exceedance

7 An example with our data (A + B + (2 * C)) / 4 = D (0.070 mg/l mg/l + (2 *0.094 mg/l)/4= mg/l

8 How long to do the OE? The results for the 10/25/2012 samples were reported on 11/12/2012 eighteen days after the samples were taken. Based on the date SID was informed of the results from the lab, the system must submit an operational evaluation within 90 days which would be 2/15/2013.

9 Pros/Cons of using the whole 90 days PRO: We planned on sampling for the next quarter on 1/17/2013. We wanted to complete the OE as soon as possible, so any changes to operations could be implemented before the next sampling event. CON: Determining what staff will perform the OE, and prepare the report. If you are a consecutive system, coordinating with another agency can be time consuming. Not enough time to obtain more data, or propose steps to prevent an MCL violation.

10 No Yes GOT GUIDANCE? GOT FORMS? Only 180 pages! That s ONLY 254 pages total! Just 74 more pages! 1.Operational Evaluation Reporting Form - 2 pages 2.Source Water Evaluation Checklist - 2 pages 3.Treatment Process Evaluation Checklist 4 pages 4.Distribution Evaluation Checklist 2 pages That s ONLY 10 pages of forms total!

11 Operational Evaluation Reporting Form Page 1 of 2 I. GENERAL INFORMATION A. Facility Information Facility Name: SID-Blue Ridge Oaks PWSID: CA Facility Address: 810 Vaca Valley Parkway, Suite 21 City: Vacaville State: CA Zip: B. Report Prepared by: (Print): Sue Murphy Date prepared: 12/15/12 (Signature): Contact Telephone Number: II. MONITORING RESULTS A. Provide the Compliance Monitoring Site(s) where the OEL was Exceeded Blue Canyon Court Note: The site name or number should correspond to a site in your Stage 2 DBPR compliance monitoring plan. B. Monitoring Results for the Site(s) Identified in II.A (include duplicate pages if there was more than one exceedance) 1. Check TTHM or HAA5 to indicate which result caused the OEL exceedance. 2. Enter your results for TTHM or HAA5 (whichever you checked above). Results from Two Quarters Ago Quarter Prior Quarter s Results Current Quarter TTHM HAA5 Operational Evaluation Value A B C D = (A+B+(2*C))/4 Date sample was collected 4/12/12 7/12/12 10/25/12 TTHM (mg/l) HAA5 (mg/l) Note: The operational evaluation value is calculated by summing the two previous quarters of TTHM or HAA5 values plus twice the current quarter value, divided by four. If the value exceeds mg/l for TTHM or mg/l for HAA5, an OEL exceedance has occurred. C. Has an OEL exceedance occurred at this location in the past? Yes If NO, proceed to item D. If YES, when did exceedance occur? No Was the cause determined for the previous exceedance(s)? Are the previous evaluations/determinations applicable to the current OEL exceedance?

12 Source Water Evaluation Checklist Page 1 of 2 NO DATA AVAILABLE System Name: SID-Blue Ridge Oaks PWS Checklist Completed by: Laura Albidress- WQ lab coordinator FF Date: 12/15/12 A. Do you have source water temperature data? If NO, proceed to item B. If YES, was the source water temperature high? If NO, proceed to item B. If YES, answer the following questions for the time period prior to the OEL exceedance. Was the raw water storage time longer than usual? Did you place another water source on-line? Were river/reservoir flow rates lower than usual? If yes, indicate the location of lower flow rates and the anticipated impact on the OEL exceedance. Did point or non-point sources in the watershed contribute to the OEL exceedance? B. Do you have data that characterizes organic matter in your source water (e.g., TOC, DOC, SUVA, color, THM formation potential)? If NO, proceed to item C. If YES, were these values higher than normal? If NO, proceed to item C. If YES, answer the following questions for the time period prior to the OEL exceedance. Did heavy rainfall or snowmelt occur in the watershed? Did you place another water source on-line? Did lake or reservoir turnover occur? Did point or non-point sources in the watershed contribute to the OEL exceedance? Did an algal bloom occur in the source water? If algal blooms were present, were appropriate algae control measures employed (e.g. addition of copper sulfate)? Did a taste and odor incident occur? C. Do you have source water bromide data? If NO, proceed to item D. If YES, were the bromide levels higher or lower than normal? If NO, proceed to item D. If YES, answer the following questions for the time period prior to the OEL exceedance. Has saltwater intrusion occurred? Are you experiencing a long-term drought? Did heavy rainfall or snowmelt occur in the watershed? Did you place another water source on-line? Are you aware of any industrial spills in the watershed?

13 Treatment Process Evaluation Checklist Page 1 of 4 NO DATA AVAILABLE Facility Name: SID-Blue Ridge Oaks PWS Checklist Completed by: Brandan Hiltman-Chief Plant Operator FF Date: 12/12/12 A. Review finished water data for the time period prior to the OEL exceedance(s) and compare to historical finished water data using the following questions: Were DBP precursors (TOC, DOC, SUVA, bromide, etc.) higher than normal? Was finished water ph higher or lower than normal? Was the finished water temperature higher than normal? Was finished water turbidity higher than normal? Was the disinfectant concentration leaving the plant(s) higher than normal? Were finished water TTHM/HAA5 levels higher than normal? Were operational and water quality data available to the system operator for effective decision making? B. Does the treatment process include predisinfection? If NO, proceed to item C. If YES, answer the following questions for the period in which an OEL exceedance occurred: Was disinfected raw water stored for an unusually long time? Were treatment plant flows lower than normal? Were treatment plant flows equally distributed among different trains? Were water temperatures high or warmer than usual? Were chlorine feed rates outside the normal range? Was a disinfectant residual present in the treatment train following predisinfection? Were online instruments utilized for process control? Did you switch to free chlorine as the oxidant? Was there a recent change (or addition) of pre-oxidant? Did you change the location of the predisinfection application? C. Does your treatment process include presedimentation? If NO, proceed to item D. If YES, answer the following questions for the period in which an OEL exceedance occurred: Were flows low? Were flows high? Were online instruments utilized for process control? Was sludge removed from the presedimentation basin? Was sludge allowed to accumulate for an excessively long time? Do you add a coagulant to your presedimentation basin? Was there a problem with the coagulant feed?

14 Distribution System Evaluation Checklist Page 1 of 2 System Name: SID-Blue Ridge Oaks PWS Checklist Completed by: Sue Murphy Date: 12/12/12 A. Do you have disinfectant residual or temperature data for the monitoring location where you experienced the OEL exceedance? If NO, proceed to item B. If YES, answer the following questions for the period in which an OEL exceedance occurred: Was the water temperature higher than normal for that time of the year at that location? Was the disinfectant residual lower than normal for that time of the year at that location? Was the disinfectant residual higher than normal for that time of the year at that location? B. Do you have maintenance records available for the time period just prior to the OEL exceedance? If NO, proceed to item C. If YES, answer the following questions: Did any line breaks or replacements occur in the vicinity of the exceedance? Were any storage tanks or reservoirs taken off-line and cleaned? Did flushing or other hydraulic disturbances (e.g., fires) occur in the vicinity of the exceedance? Were any valves operated in the vicinity of the OEL exceedances? C. If your system is metered, do you have access to historical records showing water use at individual service connections? If NO, proceed to item D. If YES, was overall water use in your system unusually low, indicating higher than normal water age? D. Do you have high-volume customers in your system (e.g., an industrial processing plant)? If NO, proceed to item E. If YES, was there a change in water use by a high-volume customer? E. Is there a finished water storage facility hydraulically upstream from the monitoring location where you experienced the OEL exceedance? If NO, proceed to item F. If YES, review storage facility operations and water quality data to answer the following questions for the period in which the OEL exceedance occurred: Was a disinfectant residual detected in the stored water or at the tank outlet? Do you know of any mixing problems with the tank or reservoir? Does the facility operate in last in-first out mode? Was the tank or reservoir drawn down more than usual prior to OEL exceedance, indicating a possible discharge of stagnant water? Was there a change in water level fluctuations that would have resulted in increased water age within the tank or reservoir?

15 Resample and expand area Date Location LAB THM (ug/l) Chlorine residual (mg/l) 10/25/ Blue Canyon Court MW /25/ Hidden Valley Lane MW /29/ Blue Canyon Court MW /29/ Hidden Valley Lane MW /29/ Blue Canyon Court BSK /29/ Hidden Valley Lane BSK /29/ Blue Canyon Court BSK /29/ Blue Canyon Court BSK /29/ Blue Canyon Court BSK /29/12 Vacant Lot BSK

16 BLUE RIDGE THMs BY SPECIES at 3436 Blue Canyon Court Currently individual analytes don t have individual MCL s just a TOTAL MCL, eventually they will be regulated individually. If you compare these individual results with examples from SSWA or GC you will see more brominated analytes in the FF water. The total THM numbers could be exactly the same say 85 ug/l but depending on the individual levels the challenges to removal will vary greatly. In SSWA/GC the main component is chloroform which is the most volatile so aeration is pretty successful. The brominated forms are less able to be removed by aeration. We are required to report FF s bromate results with the DBP for BR (quarterly) and Peabody (annually).

17 BY SPECIES: ANALYTE Chlorine residual---> 10/25/12 (ug/l) 0.2 ppm 7/12/12 (ug/l) 0.2 ppm 4/12/12 (ug/l) 0.5 ppm 1/10/12 (ug/l) 0.6 ppm 10/13/11 (ug/l) 1.7 ppm 7/14/11 (ug/l) 0.4 ppm 4/14/11 (ug/l) 0.4 ppm 1/13/11 (ug/l) 0.74 ppm Bromodichloromethane Bromoform ND Chlorodibromomethane Chloroform Total THM One of my MOST FAVORITE TABLES!! COMPOUND Molecular Weight Boiling Point Vapor Pressure Solubility (mg/l) Henry s law constant (atm-m 3 /mol) chloroform g/mol 61.2 C 159 mm Hg 7.22 x x 10-3 bromodichloromethane g/mol 90.1 C 50 mm Hg 4.5 x x 10-3 dibromochloromethane g/mol 120 C 76 mm Hg 2.7 x x 10-3 bromoform g/mol C 5 mm Hg 3.10 x x 10-3

18 List specific steps to gather more data CONCLUSIONS and STEPS to prevent MCL violations: 1. More frequent THM sampling will be scheduled for 2013 in order to have more data to follow fluctuations during different seasons. In addition to scheduled compliance monitoring quarterly for THM/HA, monthly sampling for THM only will be done at the problematic location of 3436 Blue Canyon Court. Current compliance monitoring is the third Thursday of the month. In months with compliance monitoring (Jan, Apr, Jul, Oct) THM samples will be taken on the first and third Thursday. In months with no compliance samples (Feb, Mar, May, Jun, Aug, Sep, Nov, Dec) the sample will be taken the third Thursday. 2. In response to the high result 10/25/2012 we started a weekly flushing program in the court. The chlorine residual is measured at the sample station, and then the court is flushed until the chlorine residual in the court is near the sample station level. 3. Chlorine residuals in the problem location will be taken the week of the study THM sample to get more data to see if low chlorine residuals are related to high THM results. Spreadsheets will be used to collect this data, and be submitted with quarterly SID-Blue Ridge DBP reports.

19 MORE DATA can be VERY HELPFUL!! Choose wisely you will!! SID-Blue Ridge Stage 2 THM study at 3436 Blue Canyon Court DATE THM result (ug/l) Chlorine residual (mg/l) 1/3/ /17/ /21/ /21/ /4/ /18/ /16/ /20/ /3/ /18/ /14/ /19/ /3/ /17/ /7/ /5/2013 Shaded cells are compliance Samples

20 DIRECTORS ROBERT HANSEN PRESIDENT DIV #5 GUIDO E. COLLA VICE PRESIDENT - DIV #4 JOHN D. KLUGE DIV #1 BOB BISHOP DIV #2 GLEN A. GRANT DIV#3 OFFICERS CARY KEATEN GENERAL MANAGER JAMES S. DANIELS, P.E. DISTRICT ENGINEER MINASIAN, SPRUANCE, MEITH, SOARES & SEXTON ATTORNEYS On 10/25/2012 the third quarterly samples for the schedule 1 stage 2 monitoring at SID-Blue Ridge Oaks PWS # were taken at the two compliance locations, and sent to the lab. The results for these samples were reported to SID on 11/12/2012 eighteen days after the samples were taken. The total trihalomethane result for sample location 3436 Blue Canyon Court (site no ) was 94.0 ug/l. When using the formula for determining if you have a locational running annual average operational evaluation level (OEL) exceedance : (A + B + (2 * C)) / 4 = D (where A = TTHM result for the quarter before the previous quarter (mg/l) B = TTHM result for the previous quarter (mg/l) C = TTHM result for the current quarter (mg/l) D = your Operational Evaluation Value) and D for TTHM is > mg/l, you have an OEL exceedance. Using the previous quarter s results for this location we do have an OEL exceedance. (0.070 mg/l mg/l + (2 *0.094mg/L)/4= mg/l Based on the date SID was informed of the results from the lab, the system must submit an operational evaluation within 90 days which would be 2/15/2013. We plan on sampling for the next quarter on 1/17/2013. We want to complete the OE as soon as possible, so any changes to operations can be implemented before the next sampling event. The first step in evaluating the cause of the high THM was to resample the original location, and several nearby locations. Split samples of the original location were sent to different labs. Date Location LAB THM (ug/l) Chlorine residual (mg/l) 10/25/ Blue Canyon Court MW /25/ Hidden Valley Lane MW /29/ Blue Canyon Court MW /29/ Hidden Valley Lane MW /29/ Blue Canyon Court BSK /29/ Hidden Valley Lane BSK /29/ Blue Canyon Court BSK /29/ Blue Canyon Court BSK /29/ Blue Canyon Court BSK /29/12 Vacant Lot BSK VACA VALLEY PARKWAY, SUITE 201, VACAVILLE, CA TELEPHONE (707)

21 The second step was to review which species of THM was present. The byproducts produced with PSC water differ from the ones produced from the NBA source. The NBA source produces a greater percentage of brominated species. The composition of the Blue Ridge individual THM results have increased brominated species associated with the NBA source. The city of Fairfield was contacted to participate in completing the OE forms for source and treatment. Fairfield was using 100% PSC for the first 3 days of October, and on October 4 th they switched to 100% NBA in preparation for canal cleaning. Although Fairfield did not complete any OE forms for distribution there were some changes of Fairfield s normal distribution operations during the month of October. Another change in their distribution operations when they prepare for canal cleaning is they increase storage in their tanks. Denise Drumm the Water Treatment Supervisor for the Waterman Treatment Plant suggested Laura de Albidress the Water Quality Lab Coordinator complete the OE forms for source, and Brandan E. Hiltman the Chief Plant Operator complete the OE forms for treatment. Usually on October 15 the end of the regular agricultural season, canal cleaning operations start that cause increased turbidities in the Putah South Canal raw water. In 2012 the agricultural season was extended until October 31. Rainfall records were reviewed and the rainfall in October took place AFTER the 4Q12 compliance samples were taken. Date October 21, 2012 October 22, 2012 October 23, 2012 October 24, 2012 October 25, 2012 October 31, 2012 Rainfall 0.09 inches 0.65 inches 0.01 inches 0.02 inches 0.02 inches 0.18 inches

22 Simi says: It s Fluoride o clock, this talk is over!

23 For questions or help: Sue Murphy Water Quality Specialist Solano Irrigation District