SOURCE WATER AND DISTRIBUTION SYSTEM MONITORING SELECTION, OPERATION AND MAINTENANCE OF ONLINE TOOLS

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1 SOURCE WATER AND DISTRIBUTION SYSTEM MONITORING SELECTION, OPERATION AND MAINTENANCE OF ONLINE TOOLS 2016 Plant Operations Conference Presented by the VA AWWA Plant Operations Committee Chris Griffin Regional Sales Manager Hach Company

2 TAKE HOME MESSAGES Source water and distribution system monitoring are the critical link in supplying safe water These systems are vulnerable to contamination from both internal and external sources. Baseline monitoring data and trending can help to understand the physical, chemical, and biological processes Good sampling and analysis technique assures accurate data that is actionable To be effective these tools need proper care

3 OUTLINE Overview Why Monitor your Source Water? Why Monitor you Distribution System? On-line Monitoring Best Practices Keys to Operation and Maintenance Review, Q&A

4 TYPICAL WATER TREATMENT PROCESS

5 WHAT TESTS? Tests are usually performed on grab samples. Is there a problem with grab samples?

6 TRENDING DATA ACCUMULATION Collecting baseline data is a crucial aspect of monitoring in the source water or distribution system Need to collect enough reliable data to determine: Normal variation When a deviation has occurred When the problem has been corrected

7 WHEN TO TEST? Look for trends Measurement Time

8 WHEN TO TEST? Look for trends Measurement Problem Problem Solved Time

9 WHEN TO TEST? Look for trends Desired Change Measurement Current situation Time

10 WHEN TO TEST? Look for trends Desired Change New Baseline Measurement Current situation Time

11 SOURCE WATER MONITORING It serves two basic needs: Drinking water protection Treatment control early-warning information Highlighted by recent news events

12 IN THE NEWS: ELK RIVER CONTAMINATION FREEDOM INDUSTRIES TANK SPILL

13 IN THE NEWS: POTOMAC RIVER ALGAE BLOOM

14 IN THE NEWS: OIL SPILL PATUXENT RIVER

15 IN THE NEWS: VERSO PAPER MILL LATEX SPILL POTOMAC RIVER

16 IN THE NEWS: MINE WASTE CONTAMINATION BY EPA- COLORADO RIVER

17 IN THE NEWS: COAL ASH SPILL DAN RIVER

18 MORE OF WHAT S CHANGED RECENTLY IN SOURCE WATER? Enhanced attention due to spills Eutrophication of watersheds (non-point pollution) In-reservoir treatment for algae- aeration, copper use Lead monitoring in source water? No, but the sources of corrosion change: ph, Alkalinity, Conductivity, Temp More on-line equipment and closer to source Chlorophyll, BlueGreen Algae sensors DO for diurnal cycles to gauge alga growth UVAS for Organics Non-reportable tests for monitoring

19 WHAT ARE THE EMERGING CONTAMINANTS IN SOURCE WATER: Toxic Algae - Cyanobacteria Microbiological contaminants - Naegleria fowleri (brain eating amoeba) Pharmaceuticals

GOAL: DETECT CHANGES IN BASELINE WATER QUALITY Dissolved organic matter Intrusion of another source Spring Municipal or industrial waste Acid mine drainage Produced water

20 GOAL: DETECT CHANGES IN BASELINE WATER QUALITY Dissolved organic matter Intrusion of another source Spring Municipal or industrial waste Acid mine drainage Produced water from oil and gas drilling operations Algal blooms Reservoir stratification Storm events Unintentional or Malicious contamination of the source water Chemical or Oil Spills

21 SOURCE WATER MONITORING BEST PRACTICES Good Individual parameters using portable instrumentation (ph, turbidity, DO, conductivity), grab sample back to lab Better Multiple parameters using spectrophotometer/echem meters and/or single on-line instruments. Measure for organics (TOC), bacteria, nitrate, ORP, metals, etc. Best On-line instruments monitoring continuously and real time data management

22 FOCUS ON ON-LINE BASELINE AND CHANGES IN SOURCE WATER QUALITY Recommended ph probe Dissolved Oxygen probe Conductivity probe UV Organics probe Suspended Solids/Turbidity probe ORP probe Enhanced Oil in Water probe Nitrate probe Chlorophyll TOC Alkalinity Analyzer

23 WHY THESE ON-LINE TOOLS? 23 Parameter UV 254 Organics ph Alkalinity Conductivity ORP Turbidity/Suspended Solids Dissolved Oxygen Nitrate TOC Chlorophyll A, etc. Rationale NOM, SUVA, seasonal Changes, accidental spills Acid, base relationships Organic removal, coagulant demand Change in ionic species, salt water Sudden changes in oxidative or reductive species, preoxidant control Rain event and run off changes Sudden toxic changes or algal/bacteria changes Nutrient level, agricultural runoff, MCL D/DBPR compliance, coagulation control, SUVA Changes in phytoplankton

24 24 WHERE? MEASURE AT THE SOURCE

25 WHERE? IF NOT AT THE SOURCE, THEN AT THE PLANT INLET

26 TYPICAL WATER TREATMENT PROCESS

27 OUTLINE INTRODUCTION TO THE DISTRIBUTION SYSTEM Overview Why Monitor the Distribution System? Monitoring Requirements Sampling and Testing Best Practices New ATP and PPA for field testing Review, Q&A

28 DRINKING WATER SYSTEMS What a maze!

29 DISTRIBUTION SYSTEMS - PURPOSE To convey water throughout the service area To maintain adequate pressures To provide a ready source of water for a community s health and safety To maintain a potable product Safe to drink Pleasing to the senses - palatable

30 SO, WHY WORRY ABOUT WATER IN THE DISTRIBUTION SYSTEM? Most facilities can handle most events that occur in source waters. However, once the water leaves your facility, a number of different events can compromise water quality. Water in the pipelines can become unsafe for consumption, or May no longer be palatable to your customer.

31 WHAT ARE TODAY S ISSUES IN DISTRIBUTION WATER? Nitrification control Lead and Cooper Cryptosporidium and Giardia Disinfection by Products- DBP s (THM s / HAA s) Chloramination control Maintaining residuals in longer residence times- the effects of overbuilt supply mains to housing busts after 2009 Effects of water conservation efforts on longer residence times Additional water storage to avoid expansion of water production Don t forget: Water security monitoring

32 MORE EMERGING ISSUES IN DISTRIBUTION WATER? Future regulations are moving to the tap, not point of entry Consecutive water systems, wholesale water, shared resources Enhanced attention to distribution monitoring Flushing activities to improve water quality: Flush water disposal Water conservation issues during draught auto-flushers unaccounted for water loss New line construction Main breaks

33 AND THEN.. THERE S FLINT:

34 COMMON WATER QUALITY PROBLEMS IN DISTRIBUTION SYSTEMS Chemical Biological Physical Disinfectant by-product formation Biodegradation of disinfectant byproducts Temperature increase Disinfectant decay Nitrification Sediment deposition Corrosion (lead and copper) Microbial regrowth Color Taste and odor development Taste and odor development

35 WHAT NEEDS TO BE KNOWN IN DISTRIBUTION SYSTEM MONITORING What does your distribution system consist of? What do we (should we) test for? Where do we test? How often do we test? How can we determine if something has happened in our system? How can we anticipate problems?

36 WHAT IS BEING TESTED TODAY? Frequent testing of: Coliform bacteria, chlorine, possibly ph Infrequent testing of: Lead and copper Possibly ph, turbidity, temperature, alkalinity and hardness for corrosion control (lead and copper rule) These are the minimum requirements There is no magic bullet for assessing system integrity

37 DISTRIBUTION WATER MONITORING OPTIONS Good Individual parameters using portable instrumentation (ph, chlorine, turbidity, DO, conductivity), grab sample back to lab Better Multiple parameters using spectrophotometer/echem meter and/or single process instruments. Measure for organics (TOC), bacteria (ATP), nitrate, lead & copper, etc.) Best On-line instrumentation that monitors continuously and with real time data analysis

38 FOCUS ON ON-LINE BASELINE AND CHANGES IN WATER QUALITY Recommended ph probe Chorine Analyzer Conductivity probe Suspended Solids/Turbidity probe Enhanced Ammonia Monochoramine Analyzer Dissolved Oxygen Probe ORP probe Nitrate + Nitrite probe

39 3 9 Why these on-line tools? Parameter ph Chlorine Conductivity Turbidity/Suspended Solids ORP Ammonia Monochloramine Dissolved Oxygen Nitrate+Nitrite Rationale Corrosion Pb and Cu, drop can indicate nitrification Residual disinfection Ingress or contaminant changes Ingress, bacteria, contaminant sloughage Nitrification changes Chloramination & free ammonia monitoring, successive systems Sudden toxic changes or bacteria changes Indication of nitrification issues

40 Monitoring In The Distribution System

41 TYPICAL WATER TREATMENT PROCESS

42 SESSION OUTLINE Process Instruments overview How the instruments work Keys to successful operation

43 ON-LINE INSTRUMENTS ph and ORP Ion Selective Electrodes Conductivity Turbidity and Suspended Solids Dissolved Oxygen Optical UV Wavelength Sensors Fluorescence Sensors Wet Chemistry Analyzers

44 WHAT IS ELECTROCHEMISTRY? Electrochemical measurements include: ph Ion-selective electrode (ISE)

45 HOW DOES A PH PROBE WORK? Probe measures hydrogen ion concentration Two electrodes in probe - sensing half-cell, reference half-cell

46 HALF-CELLS Ion sensing ph half cell Glass bulb that is sensitive to H +. Reference half-cell Glass tube filled with salt solution to complete circuit.

47 METER Ion Sensing Half-Cell Reference Half-Cell Ag/AgCl Wire Internal Filling Solution Reference Electrolyte Salt Bridge Junction

48 REFERENCE HALF-CELL Dispenses reference solution which completes circuit for meter

49 CALIBRATION +180 mv ph

50 CALIBRATION -180mV difference measured between ph4 and ph7 ph4 to ph7 (3 ph units) is 1000x concentration change Decade = 10-fold concentration change = 1pH unit -180/3 = mv/decade

51 KEYS TO SUCCESS New probe preparation Calibration Measurement/Storage Troubleshooting Cleaning

52 NEW PROBE Condition new ph probe in ph 7 buffer for approximately 30 minutes before initial use 7.0

53 CALIBRATE Calibrate ph systems using two or three fresh buffer solutions

54 70 NO BULK PH 10 BUFFERS PLEASE

55 CALIBRATION/VERIFICATION MEASUREMENT Probe and solution at same temperature Place probe into sample, stir, and wait for readings to stabilize Rinse and dry between measurements

56 STORAGE Short term, storage between measurements Sample or solution of similar ionic strength to sample ph4 buffer Long term Electrode storage solution (i.e. 3M KCl) Refill regularly to keep hydrated Temperature reminder, particularly freezing

57 COMMON APPLICATION ISSUES Ground loops electrical interference Bucket test, eliminate and isolate Slow response Is it Temperature? May require cleaning if slow in buffers Reference electrode drift over time Change solution and salt bridge Scratches coatings or etching of the glass electrode

58 TROUBLESHOOTING mv reading in ph 7 buffer Should read 0 30 mv in ph 7 buffer Response time Slope May require cleaning if slow in buffered solution Optimal slope is mv/decade (5%)

59 SENSOR CLEANING Solvent/Solution Hot water & detergent No more than 5% HCL acid Application For normal applications. For solutions containing lime and hydroxides. Acetone (contact Support) For solutions containing congealed oils & fats. Bleaching liquid For solutions with algae, bacteria and molds. More specific methods targeting contaminants are available

60 CLEANING Slow response may indicate need for cleaning Immerse and agitate in a warm dilute mild detergent solution for a few minutes. Rinse with DI and blot dry before use. Alternate soaking in dilute hydrochloric acid and dilute sodium hydroxide, no more than 5 minutes each Rinse with DI water and condition in ph 7 buffer before use.

61 SENSOR CLEANING Prepare soap solution Alconox Liquinox Non-lanolin dish detergent

62 SENSOR CLEANING Clean electrode surface Small soft bristle brush 1. Scrub with soap 2. Acid soak 3. Rinse 4. Soap soak

63 SENSOR CLEANING Rinse and Calibrate

64 ELECTRODE TYPICAL PROBLEMS Plugging junction Poisoning of the internal element Rapid electrolyte depletion Ground loops Reference electrodes are 90% of failures in ph measurement

65 REJUVENATING ELECTRODE

66 ION SELECTIVE ELECTRODES Electrochemistry like ph Chlorine, fluoride, nitrate, ammonia, sodium, etc.

67 HOW DO ISE SENSORS WORK? Like a ph sensor, a voltage potential is established Activity of the ion is affected by Concentration Temperature Surrounding ionic matrix

68 METER Ion Sensing Half-Cell Reference Half-Cell Ag/AgCl Wire Internal Filling Solution LaF 3 Crystal F - F - F - F - F - F - F - F - Reference Electrolyte Salt Bridge Junction

70 Chlorine Sensor 3-Electrode Sensor The measuring electrode is gold (WE), the reference electrode is silver with silver halide (RE) and the counter electrode is stainless steel (CE)

71 ISE SENSORS KEYS TO SUCCESS Each has proper ways to offset interferences Fluoride buffer for hydroxide ion Ammonia needs potassium compensation Nitrate needs chloride compensation Chlorine at proper ph Each sensor and junction must be kept free of contamination

of cartridge, components Cleaning specific to type, follow manual Air or

72 ISE SENSORS KEYS TO SUCCESS Many similar guidelines apply Proper sensor or sample line installation Regular scheduled maint. of cartridge, components Cleaning specific to type, follow manual Air or water blast system maintenance Calibration and Verification Calibration Standard Matrix adjustment

73 ISE SENSORS KEYS TO SUCCESS Additional Challenges Patience -- ISE sensors must be conditioned to their background matrix before accurate measurement More Patience -- This will take hours some preconditioning may help ISE systems do not like zero concentration and will go to sleep and give poor or no response and reaction Ammonium ISE not used for the typically low levels seen Chlorine ISE not for dechlor applications or membrane protection Make sure compensation or buffering is accurate as well as primary measurement Replace cartridge and solution at recommended guidelines

74 CONDUCTIVITY Effectively measures the the amount of dissolved salts in a fluid sc.swf sc.swf

CONDUCTIVITY CHALLENGES Proper installation for ease of maintenance Electrical noise and grounding precautions for high purity Keeping material from building up between electrodes Cleaning Wipe

75 CONDUCTIVITY CHALLENGES Proper installation for ease of maintenance Electrical noise and grounding precautions for high purity Keeping material from building up between electrodes Cleaning Wipe electrodes with soft cloth Warm mild soap solution soak for 2-3 minutes Small bristle bush, cotton swap or pipe cleaner If more needed, dilute acid soak up to 5 minutes Rinse in clean warm water Calibrate The inductive sensors can help in this regard 92

76 TURBIDITY AND SUSPENDED SOLIDS On line measurement is done with a light source and optical detection of scattered light

77 HOW A TURBIDIMETER WORKS Lamp LAMP Lens LENS Aperture APERATURE Water WATER Level LEVEL SAMPLE IN SAMPLE OUT 90 o detector 90ø DETECTOR

78 BASIC 90 O NEPHELOMETER

79 OPERATION OF TURBIDIMETERS LIGHT SOURCE 0.20 NTU 0.40 NTU 0.80 NTU DETECTOR DETECTOR DETECTOR New Lamp

80 OPERATION OF TURBIDIMETERS Measurement is a single step process, and is unable to account for light decay. Periodic calibration corrects the problem by adjusting the relationship between scattered light and corresponding turbidity(calibration gain).

81 Turbidity (NTU) Slope or gain of calibration Amount of Light Scattered

82 Turbidity (NTU) Slope or gain of calibration Amount of Light Scattered

83 0.80 Adjusted Gain Original Gain Turbidity (NTU) Amount of Light Scattered

84 KEYS FOR TURBIDIMETER USE Proper flowrate range is required Keep sample line short Use a rotameter Watch for shared sample lines Use an air gap on waste flow

KEYS FOR TURBIDIMETERS Zero the electronics in calibrate Watch for light leak or excessive bubbles Proper Maintenance Replace lamp annually

85 KEYS FOR TURBIDIMETERS Zero the electronics in calibrate Watch for light leak or excessive bubbles Proper Maintenance Replace lamp annually Clean turb body, bubble trap What can scale do to turbidity values? Keep optics (lamp, lens, photocell) clean Before calibration, not after!

86 TURBIDIMETER CALIBRATION User-Prepared Standards Dilution water and 20 NTU Formazin StablCal Standards 20 NTU Standard Solution Comparison with Lab Reading not recommended (Hach)

usually performed at low concentrations Some state

87 KEYS FOR TURBIDIMETER USE Improper (lab) comparison calibration Can cause large errors, since it is usually performed at low concentrations Some state guidelines (CA) do not recommend comparison calibration

88 PROPER TURBIDITY CALIBRATION At least once every 3 months Drain, clean and rinse sample chamber Clean the photocell Cotton swab and IPA, no abrasives Use StablCal standard Keys: invert gently for 1min, do not sit for >15 min Follow proper calibration procedure

89 SUSPENDED SOLIDS Measured optically by scattered light Additional sender and receivers Comparison calibrate to gravimetric lab samples

Turbidity: 2-channel 90 scattered light measurement in accordance with DIN EN 27027 / ISO

90 Principle of Operation For Suspended Solids: 90 & 120 scattered light measurement: Eight-channel multiple angle measurement Sender 1 Receiver 1 & Sender 2 For Turbidity: 2-channel 90 scattered light measurement in accordance with DIN EN / ISO 7027; additional measured value verification by eight-channel multiple angle measurement Receiver 3 & 4

91 SUSPENDED SOLIDS KEYS TO SUCCESS Representative installation Immersion sensor at fully mixed location Insertion sensors in full pipe, ideally in vertical Samples taken at analysis point for comparison Maintenance of optics and cleaning Change wipers (if so equipped) on schedule

92 SUSPENDED SOLIDS KEYS TO SUCCESS Locate sensor in mixed and representative sample Optic window needs to stay clean Change accessories to maintain performance

93 SUSPENDED SOLIDS KEYS TO SUCCESS Sample right at the sensor location for comparative lab analysis

94 WHAT IS DISSOLVED OXYGEN? Dissolved oxygen (DO) is molecular (atmospheric) oxygen dissolved in water or wastewater.

95 WHY IS DO IMPORTANT? Aerobic bacteria must have oxygen to survive. Rapid changes in DO levels can be cause for concern in source water (outside diurnal variations) and in distribution

96 DISSOLVED OXYGEN DO Measurement Techniques Galvanic Poloragraphic (Clark) Luminescence (LDO )

97 LUMINESCENT DO TECHNOLOGY When oxygen contacts the luminescent chemical, the intensity of the red light decreases The amount of time it takes for the material to relax is reduced Luminescent Indicator Molecules Oxygen Photo Diode Probe Sensor Clear, Gas Impermeable Substrate Gas Permeable Polymer Matrix

98 LUMINESCENT DO TECHNOLOGY The higher the oxygen concentration, the less red light that is given off by the sensor. Red Emission Light Oxygen Concentration

99 LUMINESCENT DO TECHNOLOGY The intensity of the red light is not what s being measured. What s being measured is the time it takes after excitation for red light to be given off. Lifetime of luminescence Photo Diode Probe Sensor

100 LUMINESCENT DO TECHNOLOGY A red LED is also present in the probe. Between flashes of the blue LED, a red LED of known intensity, is flashed on the sensor. The red LED acts as an internal standard (or reference) for a comparison to the red light given off by the luminescent chemical. Photo Diode Probe Sensor

101 KEYS FOR OPERATION OF LUMINESCENT DO Keep the Sensor end clean Periodic manual wiping with a clean cloth Automated Air blast

102 REDUCED MAINTENANCE CLEANING Probe Sensor Verses Photo Diode O 2 O 2 O2 Traditional Luminescent

103 KEYS FOR OPERATION OF LUMINESCENT Frequent Calibration Not Required 2 years on end cap

104 DO CALIBRATION AND VERIFICATION Per regulation or maintenance event Calibration in air Dry sensor Air, Air saturated with water Watch temperature changes Pressure/Elevation Some salinity correction

105 CALIBRATION AND VERIFICATION Calibration by comparison Can create offset issues Compare like with like Assure calibration of portable unit Sample right at sensor location Make sure equilibrated

106 OPTICAL UV WAVELENGTH SENSORS Measurement of the amount of UV light transferred to a photometer detector through a measurement path measuring gap l meß flash lamp l ref receiver

107 OPTICAL UV WAVELENGTH SENSORS Nitrate ~ 210 nm UV Organics ~ 254 nm

108 MAINTENANCE Wiper Replacement 3 to 6 month Replacement interval dependent on wiper interval Some sensors use an air blast compressor or water wiper Internal seals and optics annually

109 CALIBRATING OR VERIFICATION Periodic calibration usually not necessary Zero Offset is performed with DI Water Gain Offset is performed with Standard Solution Some use a standard filter inserted into path

110 SAC UV254 AND TOC

111 OPTICAL FLUORESCENCE SENSORS Chorophyll A Sensor Oil in Water Sensor Polycyclic Aromatic Hydrocarbons (PAH)

112 HOW THESE SENSORS WORK 162

113 MAINTENANCE Similar maintenance as the other optical sensors Standard solutions for calibrations 163

114 WET CHEMISTRY ANALYZERS Chlorine, Alkalinity, Ammonia/MonoChoramine Chemistry like bench analysis Automated color development Measured by photometer Total Organic Carbon Chemical reaction, carbon converted to CO2 and measured by NDIR

115 CL17 CHLORINE ANALYZER SAMPLE INLET SAMPLE VALVE UNDER PRESSURE LIGHT SOURCE TO WASTE INDICATOR PINCHERS GLASS CELL DETECTOR MAGNETIC STIRRER BUFFER SOLUTION

116 Light Source Detector % Transmittance Absorbance 100 ZERO READ READ READ 1.00 (Abs = -log T)

117 WET CHEMISTRY ANALYZERS Each requires a clean sample free of particles Consistent flowrate and pressure Fresh reagent replacement on schedule Cleaning of measurement cell Some analyzers have this automated Replacement of pump tubing peristaltic or finger pumps

118 TOC ANALYZER 168

119 TOC ANALYZER Wet chemistry analyzer with gas detector Compressed air Air Filter maintenace NDIR CO 2 Gas Detector Replenish reagents Every Six Months Tubing replacement Maintenance kit 169

120 ON-LINE INSTRUMENTS ph and ORP Ion Selective Electrodes Conductivity Turbidity and Suspended Solids Dissolved Oxygen Optical UV Wavelength Sensors Fluorescence Sensors Wet Chemistry Analyzers

121 TYPICAL WATER TREATMENT PROCESS

122 TAKE HOME MESSAGES Source water and distribution system monitoring are the critical link in supplying safe water These systems are vulnerable to contamination from both internal and external sources. Baseline monitoring data and trending can help to understand the physical, chemical, and biological processes Good sampling and analysis technique assures accurate data that is actionable To be effective these tools need proper care

123 SUMMARY AND QUESTIONS THANK YOU! Chris Griffin Regional Sales Manager Hach Company

Oxygen. Oxygen is one of the fundamental resources required by life forms on Earth. Aquatic ecosystems have a wide assortment of life forms.

Oxygen. Oxygen is one of the fundamental resources required by life forms on Earth. Aquatic ecosystems have a wide assortment of life forms. Oxygen Oxygen is one of the fundamental resources required by life forms on Earth. Aquatic ecosystems have a wide assortment of life forms. Oxygen is also required for some natural chemical decays. What