SESSION 7 High Turbidity Event Panel Discussion Contingency Plans and Lessons Learned Not Submitted Paul Zalenka City of Phoenix Ken Simpson City of Tempe Mr. Simpson is an AZ native, spent 16 years in agricultural and residential water distribution for a local water conservation district. 6 years with the city of Tempe as a water treatment plant operator and currently serving as a plant supervisor. Not Submitted Don Henderson City of Scottsdale Brian Paulson City of Scottsdale Brian has been with the City of Scottsdale for approximately 17 years and has worked in various capacities related to surface water treatment, wastewater treatment and groundwater treatment as well as experience in treatment related to Superfund. During his time with Scottsdale he has worked as a treatment plant operator, senior operator, coordinator and production (treatment) manager. Ray Schultz City of Peoria Ray supervises operations and maintenance of the Greenway and Quintero WTP s as well as SCADA operations of the distribution system. He has an AAS degree from Pima community College and been working in plant operations and maintenance for twenty years. He holds ADEQ certifications in WT, WWt, WD, and WWC. Vicki Sharp City of Chandler Vickie Sharp started with the City of Chandler as an Operator in 1994. She went to the Town of Gilbert in 1997 as an Operator and returned to the City of
Chandler in 2000 as the Operator III. In 2003 she moved into her current position as Water Systems Operations Superintendent. She has an Associate of Applied Sciences in Water and Wastewater from Rio Salado Community College and a Bachelor of Science in Business Management from the University of Phoenix.
February 21, 2013 Turbidity Events August 2012
Paul Zelenka, City of Phoenix Ken Simpson City of Tempe Don Henderson City of Scottsdale Brian Paulson City of Scottsdale Ray Shultz City of Peoria Vicki Sharp City of Chandler
Watershed impact from Sunflower Fire Sunflower Fire May 12 thru July 5, 2012 http://www.wrh.noaa.gov/psr/dss/sunflower.php?topic=rainfall The Verde Watershed fire will result in high NTU s when rainfall occurs.
Strategic Planning Success Plan Details Success 1 June brainstorming: Paul, Bert, Steve, Andy Plan developed 2 External Stakeholders: SRP, CAP and City of Mesa Flexible/ accommodating 3 Internal Stakeholders: Water Distribution, Water Plant and WSD Management 4 SRP: Will provide watershed updates, make emergency cuts (as needed) and use CAP if NTU exceeds 300 Excellent Communication and coordination SRP monitored NTU and made adjustments 5 CAP: Commitment to provide water to Granite Reef (GR) CAP into GR 2,000 AF 6 Review: Turbidity Event Operating Strategies Prepare Plant staff 7 Timeline: When will it arrive, duration, maximum NTU Treatment Success 8 WSO: Monsoon storage at 50-65%, Ready to use wells in NE area, Deer Valley WTP limited to 1 reservoir 8 a Val Vista: Adjusted flow based on 4,000 NTU, West plant offline and East plant flow reduced Managed system storage 60-68%, August 17 thru 24 Drinking water standards met 100% 8b Union Hills: Increase production from 120 to 160 MGD Water demands: Water transfers from Zone 4A to Zone 1 8c City of Mesa: Offline Communication benefit: City of Mesa reduced flow from 40 to 0 MGD
Sycamore Creek Granite Reef Canals WTP Water Quality Monitoring System
Turbidity Event Operating Strategies Prediction Use upstream information to make educated guesses Sycamore Creek is usually the first indicator Treatment strategies to meet drinking water standards Upstream NTU and location Collect samples run jar tests Arrival time and duration Chemical adjustments Solids handling limitations Return to normal Lessons learned
Val Vista Turbidity Timeline: August 12 30, 2012 Date Time NTU 8/13 Midnight 881 8/14 1 am 1254 8/17 2 pm 1269 8/24 11 am 880 Date Time / DT 8/17 7 pm DT= 5 Hrs Grab Online 4000 1286 8/18 Mid 1442 977 8/23 6 am 630 463 8/23 6 pm 149 161 1400 1200 1000 800 600 400 200 0 Val Vista Raw Influent NTU 8/24 7 am 761 755 8/12 8/13 8/14 8/15 8/16 8/17 8/18 8/19 8/20 8/21 8/22 8/23 8/24 8/25 8/26 8/27 8/28 8/29 8/30
Lessons Learned: Val Vista Good decision to shut off the West side and reduce production A reduced production rate on the East side helped to keep the plant meeting treatment goals.
Arizona Canal Turbidity Timeline: August 12 30, 2012 Date Time NTU 8/17 3 pm 1365 8/24 2 am 625 WTP Date Time/ DT 24 th 8/18 11 am DT=20 DV 8/18 10 pm DT=+14 24th 8/25 1 am DT =23 DV 8/25 1 pm DT=+12 Grab Online 3400 815 935 351 293 221
Lessons Learned: 24 th Street WTP Optimize sludge removal from the pre-sed basin. Lessons Learned: Deer Valley WTP Optimize the sand concentration in the sand ballasted flocculation process. Possibly use a different polymer during high turbidity events.
Canal NTU Meters and Observations Canal travel time estimates are not always accurate Canal turbidity meters maximum range was 1300. Actual turbidity was over 4,000 NTU Granite Reef turbidimeters and creek flows are very valuable.
Lessons Learned: City of Tempe
Lessons Learned: City of Tempe
Lessons Learned: City of Scottsdale Chaparral WTP impacts of high NTU on membranes Solids handling impacts Elevated membrane permeate TOC
Lessons Learned: City of Peoria Greenway WTP, being at the end of the AZ canal, sees quite a bit less turbidity than upstream facilities. However, water quality (alkalinity, color, chlorine demand, taste & odor) were similar to upstream plants. Plan for the worst case. Be organized before poor water quality enters your facility. Communication with upstream WTP s is essential. Ensure staff is trained (and re-trained!) and chemicals are prepared and not outdated to perform jar testing.
Lessons Learned: City of Chandler Do not be shy in increasing the alum dosage, as soon as there is a spike in NTU's. It is better to be overfeeding at the beginning of the event than try and play catch up once the turbidity is in the plant. Take a cut in production from SRP. We ended up having to shut our plant down for 12 hours due to this event.