Improving WTP Performance Tools to Help Achieve Optimization Partnership for Safe Water 2015 Water System Optimization Conference; Hershey, PA Michael W. Grimm, P.E. Aquamize, LLC October 29, 2015 1
Today s Outline 1. Introduction to Optimization 2. Examining processes & procedures 3. What can be learned from data? * Historical data * Special studies 4. Physical inspections 5. Invasive tactics Start with the Big Picture Overview 2
Introduction What is Optimization? Highest possible level of WTP performance? Can a WTP produce safe drinking water without being optimized? So, why should a WTP be optimized? 3
Introduction Is a WTP the only part of a water system that can be optimized? * Human Resources: Operator training, workforce retention * Finance: Comprehensive audits * Infrastructure: Asset management plans * Distribution operations: Water loss audits, flushing programs, water quality monitoring, operational procedures, O&M manual, etc. 4
WTP Optimization Review current operational procedures Assess operator input Review historical water quality and process data Collect new data regarding current status Visually inspect processes and conditions Conduct invasive tests and experiments 5
Operational Procedures & Input Do operators have a standard set of operating procedures that are followed? Are those SOPs embraced by all operators? Do the SOPs outline which buttons to push or which knobs to turn, or do SOPs lead thinking? Do operators work together from the same page? WTP have mindset in place to pursue optimization? 6
Historical Data What data is collected to assess WTP performance? Where is it collected, where is it stored? Is it utilized routinely by the operators to maintain the WTP processes? Can trends be examined and assessed from the historical data? 7
Turbidity Trend Profile 100 Raw Max Filtered Max Settled Combined 10 Turbidity (NTU) 1 0.1 0.01 Jan-13 Feb-13 Mar-13 Apr-13 May-13 Jun-13 Jul-13 Aug-13 Sep-13 Oct-13 Nov-13 Dec-13 Jan-14
Turbidity Trend Profile 10 Raw Max Filtered Combined 1 Turbidity (NTU) 0.1 0.01 May-13 Jun-13 Jul-13 Aug-13 Sep-13 Oct-13 Nov-13 Dec-13 Jan-14 Feb-14 Mar-14 Apr-14 May-14
Turbidity Trend Profile 100 Raw Max Filtered Combined 10 Turbidity (NTU) 1 0.1 0.01 Jan-14 Feb-14 Mar-14 Apr-14 May-14 Jun-14 Jul-14 Aug-14 Sep-14 Oct-14 Nov-14 Dec-14 Jan-15
Turbidity Profile: IFE w/ Raw 24-Hour Time Period 0.7 12 0.6 0.5 0.4 0.3 Filter 1 Filter 2 Filter 3 Filter 4 Raw 10 8 6 0.2 4 0.1 2 0 0
IFE Turbidity Data 72 Hours 0.4 0.35 0.3 Filter 1 Filter 2 Filter 3 0.25 0.2 0.15 0.1 0.05 0 June 18 June 19 June 20
Special Studies Data Settled water evaluation Backwash water & process evaluation Filtered water turbidity evaluation Jar testing evaluation for chemical dose verification 13
Settled Water Turbidity Evaluation Does the settled water meet turbidity goals for < 2 NTU for raw water at or above 10 NTU and < 1 NTU for raw water < 10 NTU? Is there short circuiting within the basin? Is there an observable drop zone in the basin or area within a basin? Set special study to monitor turbidity in basin. 14
Establish monitoring locations in basins to determine if turbidity is higher in specific areas of the basin & launders
Collect samples at set time intervals Transfer to labeled bottles for analysis
Turbidity Data by Monitoring Location 1.2 1 0.8 0.6 Filter 2 Filter 1 0.4 0.2 0 0 1 2 3 4 5 6 7 8 9
Clarifier Comparison Turbidity Profile: 1st Run 3 Turbidity (NTUs) 2.5 2 1.5 1 Side 1 Side 2 0.5 0 A B C A B C A B Raw Floculator Trough Sed Basin Filter Treatment Stages
Backwash Evaluation Measure the media (filter bed) expansion during a backwash Measure the backwash rate and compare to metered values Observe backwash process noting the timing and duration of each stage Observe effectiveness of the backwash Collect water samples to measure turbidity being released by the backwash water 20
Use secchi disk or pipe flute tool to measure fluidized level of the anthracite media from reference point
Filter Observations During BW Area of more violent air scour upflow through the filter media.
Backwash Rate Evaluation Backwash (BW) pumps are usually metered Record BW pump meter reading and duration of BW event to calculate a flow rate (volume divided by time) Use SCADA system data if that is available Keep historical records to tract changes What if there is no pump, there is no meter, and there is no way measure water into filter? 24
Backwash Rate Evaluation Be clever!! Assume water coming into the filter as backwash supply is the same as entering the washwater holding basin Measure the rise of expansion in the holding basin over the backwash event From the known surface area of the holding basin, calculate the volume of water for every inch increase in the basin Calculate the flow in terms of volume / time 25
Backwash Rate Evaluation - Example In the decant (holding) basin, a 1-inch depth = 202 gallons During the backwash event, the decant basin rose 17 inches during the 12 minute backwash event The total backwash volume used = (202 gallons / inch) x (17 inches) = 3434 gallons The filter basin surface area = 36 ft 2 The backwash rate = (3434 gallons)/(12 min x 36 ft 2 ) = 8 gpm/ft 2. The WTP thought the rate was 15 gpm/ft 2 ooops 26
Backwash Water Comparison Turbidity vs. Time (minutes) 35.0 30.0 25.0 20.0 15.0 Filter 1 Filter 2 10.0 5.0 0.0 1 3 4 6 8 10 12 15
Filtered Water Turbidity After BW Select sample location to get timely representative samples Use bench model turbidimeter that is properly calibrated If possible, compare to on-line turbidimeter to determine compatibility Collect up to 25 samples to create a good profile curve 28
Filter 1 Turbidity Comparison Turbidity vs. Time (minutes) 0.45 0.4 0.35 0.3 0.25 0.2 Grab On-line 0.15 0.1 0.05 0 1 5 6 7 8 9 10 11 12 14 16 17.3 22.3 25 28.8
Filter 2 Turbidity Comparison Turbidity vs. Time (minutes) 0.4 0.35 0.3 0.25 0.2 Grab On-line 0.15 0.1 0.05 0 1 4 10 12 13 14 16 18 19.5 21 24 27 30 34
Turbidity Profile after Backwash 0.45 0.4 0.35 Turbidity (NTU) 0.3 0.25 0.2 0.15 0.1 0.05 0 0 1 2 3 4 5 6 7 7.5 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 Time (Minutes)
Media Surface Examination Look for mounding or depressions in the media Look for media pulling away from interior sides of the filter basin Look for mudballs or a blinding floc blanket on the media surface Examine the surface wash arms & nozzles and assess their operability 32
Filter Media Surface Inspection
Surface depression area Surface mounding area Filter core location Box excavation location Clarifier Wall Filter 1 - Back Filter Feet 20 15 10 5 40 44 27 26 43 39 43 40 42 43 39 5 Probe depth (in) Feet 39 39 43 43 40 41 10 42 40 27 26 43.5 43.5 13 Front Filter Wall
Invasive Media Examination Invasive meaning getting into the filter basin Lower platform to stand on filter w/out standing directly on the media Examine surface of media & equipment Probe media with coring bar (steel rebar) Core media in specific locations Excavate media inside a small box 41
Using a box excavation, the media can be thoroughly examined
Core Sample Turbidity Analysis Collect media from core samples preserving the relative depth of the sample label bag Each core sample should yield 4-5 media samples (1 per bag) Follow standard protocol for rinsing each media sample with tap water and pouring off liquid Repeat rinsing process to collect 500 mls of water Stir collected water and analyze sample turbidity Turbidity values at each core depth = floc retention profile 49
0.0 Filter 2 Floc Retention Profile -5.0 Depth Below Media Surface (Inches) -10.0-15.0-20.0-25.0 Core 15/5 Dirty Core 4/1 Dirty Core 4/1 After Backwash 0 100 200 300 400 500 600 700 Turbidity (NTU)
FILTER 1 Floc Retention Profile - April 2014 0.0-2.0 Depth Below Media Surface (Inches) -4.0-6.0-8.0-10.0-12.0-14.0-16.0-18.0 Filter 1 - Core 4-5 (Dirty) - April Filter 1 - Core 4-5 (Clean) - April 0 50 100 150 200 250 300 350
Depth Below Media Surface (Inches) 0.0-5.0-10.0-15.0-20.0-25.0-30.0 FILTER 2 Floc Retention Profile - April 2014 Pre- BW Post-BW 0 100 200 300 400 500
0.0 Filter 2 Floc Retention Profile -5.0 Depth Below Media Surface (Inches) -10.0-15.0-20.0-25.0 Core 15/5 Dirty Core 4/1 Dirty Core 4/1 After Backwash 0 100 200 300 400 500 600 700 Turbidity (NTU)
How Can You Get Started? Develop the culture to pursue optimization Establish goals and a plan to achieve the goals Garner input from all staff and develop SOPs to achieve goals Establish benchmarking tools to monitor progress Use resources available Hire consulting assistance 54
Thank you for attending the presentation! Questions or comments? Michael W. Grimm, P.E. Phone: 503-260-4405 Email: aquamize@gmail.com 55