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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 BoardDivision of Drinking Water (DDW)

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Your Moderator Today…

Jean Thompson-Ibbeson

jthompson@rcac.org

Your Moderator Today…

Neil WorthenLas Cruces, NM

nworthen@rcac.org

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The Rural Community Assistance Partnership

RCAC

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Marking Tool

Hide/Restore Control Panel

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Control Tabs

Audio Controls

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Attendee List

Today’s Materials

Questions?

Text your questions and comments anytime during the session

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Your Trainer Today

John Hamner

Rural Development Specialist –Environmental

jhamner@rcac.org

Regulations Basics Online Session #4 Surface Water

Treatment

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Regulations Basics OnlineLearning 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

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Water Treatment History

Earliest recorded treatment of water = 300 BC (boiling, Hippocratic sleeve)

In the 13th 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

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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

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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)

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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

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Marking Tool

Hide/Restore Control Panel

Any “rules” really annoy you?

Disinfection by Product

Public Notification

Surface Water Treatment

Lead and Copper

RTCR

Arsenic

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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

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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 monitoringSystem specific/Statewide information

needed

Lead and copper rule and corrosion controlStates to determine appropriate

treatment

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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)

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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

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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

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CHAPTER 15. DOMESTIC WATER QUALITY AND MONITORING

REGULATIONS

Determines the Best Available Technology (BAT) for removal of;

Microbial contaminants

Inorganic chemicals

Radionuclides

Organic chemicals

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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

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Best Available Technology

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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

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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

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Marking Tool

Hide/Restore Control Panel

What could cause your treatment process to change?

Source quality System demand

Regulations

My DE Technology

Other Science

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Questions?

Text your questions and comments anytime during the session

5 minute break

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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)

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Treatment Techniques

Chemicals

Pre-disinfection/oxidation

Coagulants/polymers

pH adjustments

Treatment Techniques

Chlorine

Gas, liquid & HTH

Chlorine dioxide

Chloramines

Ultraviolet light

Ozone

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Conventional Water Treatment

1.Coagulation

2.Flocculation

3.Sedimentation

4.Filtration

Chemicals

Flash Mix

Stage 1

Flocculation

Stage 2

Sedimentation

Stage 3

Filtration

Stage 4

Polymer

Solids Recirculation

Basic Water Treatment Plant Flow

UV/Cl2

Oxidizer/coagulant

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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

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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)

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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

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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

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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

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Conventional Clarifier

Questions?

Text your questions and comments anytime during the session

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TURBIDITY REMOVAL – Text Box

Why worry about turbidity?

What is turbidity?

Turbidity…Filtration plants remove it

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Filtration Basics

Conventional Vs. Direct

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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

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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

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Slow Sand Filter

Slow Sand Filter

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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

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How do Membranes Work?

Contaminants such as bacteria and viruses can not pass

through the membrane’s pores

Water molecules and dissolved salts pass freely through the

membrane pores

Semi permeable membrane wall with microscopic pores

Filtration Flow

Filtration flow may be from the outside into the membrane hollow fiber or from the inside to the outside

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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

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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

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Taste And Odor Control

Treatment:

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

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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

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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

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Protozoa

Single cell

> 10 um

Primitive to complex structures

Free living and parasitic species

Disinfection Methods

Physical methods

Ultraviolet rays (UV)

Chemical methods

Chlorine

Gas, liquid, HTH

Chloramines

Chlorine dioxide

Ozone

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U-V Tube

U-V Unit

Chlorine Gas – Ton Containers

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Ton Containers – Feed System

Chlorination Mechanics

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Chlorine Gas Feed System

Chlorine Products - Liquid

Sodium hypochlorite (bleach) NaOCI

Comes in gallon jugs or bulk

5.25,12.5-15% available chlorine

Explosive when combined with HTH

Ruins clothing

Raises pH of water treated

Fed with hypochlorinator (positive displacement pump)

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Chlorination Mechanics

Chlorination Mechanics

Sodium hypochlorite injection system

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Calcium Hypochlorite

ChloraminesCompounds 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

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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

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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

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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

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Questions?

Text your questions and comments anytime during the session

Resources

California Drinking Water Regulations http://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/documents/lawbook/dwregulations-2014-07-01.pdf

Water Board web site

http://www.waterboards.ca.gov/drinking_water/programs/index.shtml

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http://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/TMF.shtml

Scroll Down

114LINKS TO RESOURCES

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Thank You For Attending!

We look forward to seeing you

in future online classes!

jthompson@rcac.org

jhamner@rcac.org

Thank You For Attending!

Neil Worthennworthen@rcac.org

(575) 527-5372