Regulations Basics Online Session #4 Surface Water Treatment WELCOME!

Transcription

1 Regulations Basics Online Session #4 Surface Water Treatment WELCOME! This training is presented by RCAC with funding provided by the California State Water Resources Control Board Division of Drinking Water (DDW) 1

2 Your Moderator Today Jean Thompson- Ibbeson Your Moderator Today Neil Worthen Las Cruces, NM 2

3 The Rural Community Assistance Partnership RCAC Affordable housing Community facilities RCAC Programs Water and wastewater infrastructure financing (Loan Fund) Classroom and online training On-site technical assistance Median Household Income (MHI) surveys 3

4 Performance Assessment Rating Tool (PART) 4 to 6 weeks from today w/ today s workshop in subject line 2 questions 3 minutes maximum How did you use the information that was presented today? Funders are looking for positive changes Help us continue these free workshops! Hide/Restore Control Panel Marking Tool 4

5 Control Tabs Audio Controls 5

6 Attendee List Today s Materials Questions? Text your questions and comments anytime during the session 6

7 Your Trainer Today John Hamner Rural Development Specialist Environmental Regulations Basics Online Session #4 Surface Water Treatment 7

8 Regulations Basics Online Learning Objectives Provide Operators with a working knowledge of the California Safe Drinking Water Act Basic water treatment techniques Continue to provide safe water to your customers Today s Agenda Background Importance of surface water treatment standards Surface Water Treatment Rule (SWTR) History & development of the SWTR Treatment Techniques Monitoring & Reporting Additional Resources 8

9 Water Treatment History Earliest recorded treatment of water = 300 BC (boiling, Hippocratic sleeve) In the 13 th century, Egyptian tombs showed water treatment drawings In 1804 the first recorded citywide water treatment plant was installed in Paisley, Scotland Water Treatment in the USA Slow sand filters introduced in the United States around 1870 Modern rapid-sand filtration plant built in 1902 at Little Falls, NJ In 1909, liquid chlorine was used for disinfection of water supplies Drinking water regulations began developing state by state 9

10 Chlorination History Surface Water Treatment All surface water supplies are assumed to contain pathogenic microbial contaminants Treatment Operators need to be knowledgeable and technically proficient in surface water treatment operations California Safe Drinking Water Act regulations set the minimum standards for the treatment of surface water supplies 10

11 Poll Time! Question 1: What were you doing in the 70 s? Do you even remember the 70 s? In early 1970 s a series of environmental acts are passed by congress Clean Air Act Clean Water Act Formation of the Environmental Protection Agency (EPA) Safe Drinking Water Act (SDWA) 11

12 EPA Established December 1970 Drinking water program moved from Public Health Service to EPA First inventory of community water systems in USA is conducted EPA works towards federal drinking water guidelines SDWA approved by Congress Congress approves SDWA in 1974 SDWA goes into effect June 1977 Amended in 1986 and 1996 Amendments are called rules 12

13 Hide/Restore Control Panel Marking Tool Any rules really annoy you? Disinfection by Product Public Notification Surface Water Treatment RTCR Lead and Copper Arsenic 13

14 The Original SDWA Original SDWA set standards for: Microbial contaminants Ten inorganic chemicals Six organic pesticides Turbidity Radiological contamination Concept of primacy 1986 Amendments 83 contaminants monitored in 3 years Additional 25 contaminants every 3 years Added ground water protection program Creation of NTNC category water system Organic chemicals Public notification 14

15 SDWA 1986 Amendments Ground Water Under the Direct Influence GWUDI Surface water treatment rule Higher filtered water standards CT calculations Effects of 1986 Amendments Waivers and exemptions from chemical monitoring System specific/statewide information needed Lead and copper rule and corrosion control States to determine appropriate treatment 15

16 Poll Time! Question 2: How many lead and copper samples do you take each sampling cycle? 1996 Amendment High Lights Source Water Protection Capacity development (TMF) Consumer Confidence Reports New, science based contaminant selection State Revolving Loan Fund (SRF) 16

17 1996 Amendment High Lights Radon Arsenic Cryptosporidium Sulfate Disinfection by Products (DBP) Distribution operator certification Questions? Text your questions and comments anytime during the session 17

18 Poll Time! Question 3: How often do you refer to the California SDWA? CHAPTER 15. DOMESTIC WATER QUALITY AND MONITORING REGULATIONS Determines what will be tested for in raw water; Bacteria Nitrite/nitrate Inorganic/organic chemicals Fluoride Radioactivity Secondary standards 18

19 CHAPTER 15. DOMESTIC WATER QUALITY AND MONITORING REGULATIONS Determines the Best Available Technology (BAT) for removal of; Microbial contaminants Inorganic chemicals Radionuclides Organic chemicals 19

20 BAT CHAPTER 15. DOMESTIC WATER QUALITY AND MONITORING REGULATIONS The Best Available Technology (BAT) for removal of these constituents is generally; Microbial contaminants Inorganic chemicals Radionuclides Organic chemicals 20

21 Best Available Technology 21

22 CHAPTER 15. DOMESTIC WATER QUALITY AND MONITORING REGULATIONS Classification of Facilities based on water quality and monitoring; Bacteria Nitrite/nitrate Inorganic/organic chemicals Fluoride Radioactivity Secondary standards 22

23 Add up the points Now That This Has Been Established Systems have already been assessed However, system assessments can change due to; Change in water source Change in water quality Change in water regulations Change in Health Department Staff 23

24 Hide/Restore Control Panel Marking Tool What could cause your treatment process to change? Source quality System demand Regulations My DE Technology Other Science 24

25 Questions? Text your questions and comments anytime during the session 5 minute break 25

26 Poll Time! Question 4: What type of treatment do you utilize at your facility? Treatment Techniques Physical Conventional filtration Direct filtration Slow sand filtration Bag filters Membrane filtration Other (text) 26

27 Treatment Techniques Chemicals Pre-disinfection/oxidation Coagulants/polymers ph adjustments Treatment Techniques Chlorine Gas, liquid & HTH Chlorine dioxide Chloramines Ultraviolet light Ozone 27

28 Conventional Water Treatment 1.Coagulation 2.Flocculation 3.Sedimentation 4.Filtration Basic Water Treatment Plant Flow Oxidizer/coagulant Chemicals Polymer UV/Cl2 Solids Recirculation Flash Mix Flocculation Sedimentation Filtration Stage 1 Stage 2 Stage 3 Stage 4 28

29 Coagulation - Types Primary coagulants Neutralize the electrical charge of particles in water, which allows them to clump together (gain weight) Coagulant aids Add density to slow settling floc and adds toughness so floc will not break up (shear) in following processes Coagulants How they work Metallic salts: Create a series of reactions with the water and other ions in the water resulting in floc Reactions are due to opposing electrical charge of coagulant and particulates Floc adsorbs to turbidity in the water 29

30 Coagulants How They Work Basic Coagulation Chemistry Coagulation = physical and chemical reaction between alkalinity and coagulant, which forms insoluble floc Neutral and lower ph waters favor positive floc due to negative charge of particulates Best ph for coagulation is 5-7 Proper ph must be maintained (residual alkalinity prevents ph from changing) 30

31 Coagulation - Dosage Dosage is determined by the jar test Multiple liter jars filled with raw water Placed on mixer to imitate flash mix Coagulant added in milligrams (mg) Water and coagulants mixed Mixer turned off, observe settleability Best dosage in mg/l, apply to system Process Control Jar Testing 31

32 Flocculation Flocculation provides a slow, gentle agitation of the water and coagulants Transforms smaller particles of floc formed by flash mix into larger floc Rate of floc growth depended on rate at which smaller floc collides Larger floc more fragile, slow mixing important to reduce shearing Water slowed to reduce short circuiting Horizontal Flocculator 32

33 Vertical Flocculator Sedimentation/Clarification Basins Removal of settleable solids by gravity Usually steel or concrete basins May be rectangular, square or round Allows water to flow very slowly 33

34 Conventional Clarifier Questions? Text your questions and comments anytime during the session 34

35 TURBIDITY REMOVAL Text Box What is turbidity? Why worry about turbidity? Turbidity Filtration plants remove it 35

36 Filtration Basics Conventional Vs. Direct 36

37 Conventional Treatment & Disinfection Process coagulation flocculation sedimentation filtration disinfection Pros Removal capabilities Ability to treat source waters of low or inconsistent quality Conventional Treatment Cons Advanced level operator needed Adequate land High costs Sludge disposal 37

38 Filtration - Types Dual media bed of sand used as support media, anthracite coal on the top Multi media three or more types of media with varying size & specific gravity Slow sand water slowly fed through a large bed of sand Diatomaceous earth (DE) Under pressure, water is forced through a filter element that is coated with DE Multi Media 38

39 Slow Sand Filter Slow Sand Filter 39

40 Membranes Text Box Do you use membrane filtration in your system? If so, what type? Description of membrane process Water forced through a porous membrane under pressure while larger molecules are held back Reverse Osmosis Microfiltration Ultrafiltration Nanofiltration 40

41 How do Membranes Work? Water molecules and dissolved salts pass freely through the membrane pores Semi permeable membrane wall with microscopic pores Contaminants such as bacteria and viruses can not pass through the membrane s pores Filtration Flow Filtration flow may be from the outside into the membrane hollow fiber or from the inside to the outside 82 41

42 Types of DW Membranes Microfiltration Ultrafiltration Reverse Osmosis Nanofiltration Fine particulate removal Dissolved solids removal Membranes Microfiltration (MF) and ultrafiltration (UF) are used in water treatment for the removal of the following constituents: Algae Bacteria and viruses Particles Sediment 84 42

43 Ion Exchange Nitrates (NO3) Cause Nitrates come from human and animal waste Effect Nitrate can create methemoglobinemia (blue baby disease) in small children Treatment The BAT is ion exchange, coupled with reverse osmosis Taste And Odor Problems Cause: Biological growth algae, bacteria, diatoms, flagellates and fungi Treatment/distribution systems poor housekeeping, chlorine Environmental oxygen depletion in reservoirs due to stratification Pollution wastewater, industrial wastes, chemical spills, urban runoff and agricultural waste 43

44 Treatment: Taste And Odor Control Coagulation, flocculation, sedimentation Aeration, with volatile gasses and organic compounds only Air stripping (air diffusers) Chlorine, chlorine dioxide, potassium permanganate, ozone PAC (powdered activated carbon) or GAC (granular activated carbon) Questions? Text your questions and comments anytime during the session 44

45 Poll Time! Question 5: What type of disinfectant do you utilize at your facility? Disinfection & Oxidation Purpose: To kill or inactivate all pathogens Taste and odor control Helps coagulation process Helps filtration process Algae control 45

46 Bacteria Single cell 0.1 to 10 um Four shapes: spheroid, rod, spiral and filamentous Viruses 0.01 to 0.1 um Composed of DNA or RNA with protein coat Generally very species specific 46

47 Protozoa Single cell > 10 um Primitive to complex structures Free living and parasitic species Physical methods Ultraviolet rays (UV) Disinfection Methods Chemical methods Chlorine Gas, liquid, HTH Chloramines Chlorine dioxide Ozone 47

48 U-V Unit U-V Tube Chlorine Gas Ton Containers 48

49 Ton Containers Feed System Chlorination Mechanics 49

50 Chlorine Gas Feed System Chlorine Products - Liquid Sodium hypochlorite (bleach) NaOCI Comes in gallon jugs or bulk 5.25, % available chlorine Explosive when combined with HTH Ruins clothing Raises ph of water treated Fed with hypochlorinator (positive displacement pump) 50

51 Chlorination Mechanics Chlorination Mechanics Sodium hypochlorite injection system 51

52 Calcium Hypochlorite Chloramines Compounds formed by the reaction of hypochlorous acid with ammonia Water usually treated, chlorinated and gaseous (or liquid) ammonia added, but can be added before or during chlorine addition Ammonia is liquefied compressed gas in cylinders or one ton containers or liquid form (most common) Usually mixed at 3:1 or 4:1 ratio, chlorine to ammonia 52

53 Chlorine Dioxide CIO2 Must be generated on site (unstable) combining sodium chlorite (liquid or powder) and chlorine solutions at low ph Greenish yellow gas, odorous Powerful oxidant Developed to aid in taste and odor issues Chlorine Dioxide CIO2 - Pros Lack of TTHM formation Effective killing bacteria and viruses Does not combine with ammonia Oxidizes iron and manganese Removes color Taste and odor control Somewhat effective against cryptosporidium Does not create carcinogens 53

54 Chlorine Dioxide CIO2 - Cons Can create chlorates and chlorites which may cause anemia in some folks (unless you add ferrous sulphate) Gives water distinct taste, undesirable to some Higher level operator needed Cat urine odor (with new Carpet) Ozone (O3) Bluish, toxic gas with pungent odor Ozone generated by passing a high voltage between two electrodes allowing the O2 to split, reattach and become O3 Oxygen must be dry, and particle free Very effective disinfectant, powerful oxidizer Must be generated on site, not transportable 54

55 Ozone (O3) - Pros Very effective disinfectant, not proven to be carcinogenic (if no bromide exists) Also effective for color, taste and odor Less likely to create disinfection by products, assuming no bromide (creates Bromate) Improves coagulation process, which lowers chemical cost, reduces sludge disposal and lengthens filter runs Ozone (O3) - Cons Equipment is expensive High electrical costs Residual does not last Need to add disinfectant with residual afterwards Large foot print Higher level operator needed 55

56 Questions? Text your questions and comments anytime during the session Resources California Drinking Water Regulations ater/certlic/drinkingwater/documents/lawbo ok/dwregulations pdf Water Board web site ater/programs/index.shtml 56

57 Scroll Down LINKS TO RESOURCES

58 Thank You For Attending! We look forward to seeing you in future online classes! Thank You For Attending! Neil Worthen (575)