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Surviving a Boil Water

Advisory

Dave Maynard

Environmental Quality Analyst

Michigan Department of Environmental Quality

Resource Management Division

Cadillac District Office

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Overview

This presentation will cover:

• What is a Boil Water Advisory (BWA)

• Ways to Avoid a BWA

• Reasons for a BWA (with a focus on

coliform bacteria)

• How and When to Distribute a BWA

Notice

• How and When to Rescind a BWA Notice

• Follow up Requirements after the BWA

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What is a BWA?

• A BWA is defined by DEQ Policy as a written or verbal advisory issued by the water system or the DEQ notifying consumers that the water may be contaminated and advising them to boil the water before using it for drinking cooking.

• There may be situations where water system contamination is not microbial but due to chemical contamination. In these cases a “Do Not Use” notice will be distributed.

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Ways to Avoid Water System

Contamination and a BWA • Adequate chlorination; keep good chlorine residual

records, look for a problem if residuals suddenly drop

• Adequate monitoring of construction chlorination and bacteriological sampling (per AWWA Standard C651)

• Adequate cross connection control program including home inspections

• Adequate flushing program; flow must be at least 2.5 feet per second, best if unidirectional, flush out from the pressure source high to low

• Elevated storage tanks should be turned over once every 24 hours to maintain chlorine residual adequate for the suppression of bacteriological growth (Pizzi 1996)

Ways to Avoid Water System Contamination

and a BWA Continued

• Perform routine inspections of

underground and elevated storage

reservoirs

• Establish project-specific standard

operating procedures. For example, be

sure all valves shut down prior to a project

are re-opened once completed.

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Reasons for a Boil Water

Advisory (BWA)

Coliform and or an E. coli Bacteria Maximum

Contaminant Level (MCL) Violation

Surface Water Treatment Rule (SWTR)

Treatment Technique (TT) Violations

Waterborne Disease Outbreaks

Loss of Pressure

Low Pressure

Water Main Breaks or Repairs

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Coliform and or an E. coli

Bacteria MCL Violation

What is coliform bacteria?

A broad class of bacteria found everywhere in our environment, including the feces of humans and other warm-blooded animals.

E. Coli bacteria is a member of the coliform group of bacteria.

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Total Coliform Bacteria Group

Drinking Water System

Environment Total Coliform Bacteria Group

= Environmental Contamination

E. coli Bacteria

Viruses and protozoa - not

part of the coliform bacteria

group but are still harmful

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Why test for coliform bacteria?

Drinking water must be free of

disease-causing organisms such as viruses, protozoa, and E. coli bacteria. Testing for all of these is time consuming and expensive.

Because coliform bacteria fairly common in the environment and testing for them is relatively inexpensive they were selected as an “indicator organism”.

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What is a coliform maximum

contaminant level (MCL) violation? Systems required to collect

less than 40 samples per

month (population served

under 33,000)

If 2 or more routine

distribution or repeat samples

are coliform or E. coli-positive

Systems required to collect

40 samples or more per

month (population served

33,000 or more)

If 5 % or more of routine

distribution or repeat samples

are coliform or E. coli positive.

•Any routine E. coli positive sample followed with an E. coli

positive repeat sample

•Any total coliform positive repeat sample followed with E.

coli positive repeat sample

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How do coliforms and other

pathogens enter the drinking water

system? • Improper chlorination after construction or

repairs

• Storage tank hatch malfunction

• Underground storage tank breeches

• Short term pressure losses in the distribution system caused by pump start/stops, main breaks, rapid opening and closing of valves, loss of power, and hydrant flushing (Kirkmeyer et al, 1999).

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Biofilm: A Hideout for Coliform Bacteria

Because coliforms

are able to survive

and re-grow in a

distribution system

(LeChevallier 1990)

their presence does

not necessarily

indicate recent

contamination.

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Biofilm Development

Montana State University Center for Biofilm Engineering

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What influences the growth rate of

coliforms/pathogens in a water

system?

• Chlorine Residual

• Water Temperature

• Nutrients: limiting factors of growth are dissolved organic carbon and phosphorous (Miettinen et al 1997).

• Oil for lubricating well pumps has been associated with coliforms (White & LeChevallier 1993).

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If you receive a routine coliform or E.

coli-positive, complete the following

within 24 hours:

• Review your Sample Siting Plan

• Collect a sample at the original positive site

• Collect a sample within 5 service connections upstream

• Collect a sample within 5 service connections downstream

• Collect a sample at an additional site

• Collect a raw water sample from each well. Wells that were not operating within 72 hours of may be excluded under DEQ approval. Each well must be sampled per the number of distribution positives, e.g. 2 distribution positive means 2 per well

• If normally take 2 or more monthly than only 3 repeat are needed

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If a routine sample is coliform-positive, the

duration of a BWA may be shortened by

doing these things immediately:

• If your system is chlorinated, increase the dosage and track residuals at the ends of the system. Chlorine residual “sag” or disappearance may help locate the source of the bacteriological contamination.

• If your system is not chlorinated, begin emergency chlorination immediately.

• Spike storage tanks.

• Feed about 2 mg/l and maintain at least 0.7 free residual at ends of system

• Begin flushing to clear out contamination and to bring chlorine into the system

• Look for a problem, check storage tanks, booster stations, etc.

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What if a repeat sample is coliform

or E. coli positive?

The DEQ will require issuance of a BWA

in most cases of a coliform bacteria MCL.

The DEQ will require a BWA in all cases of

a coliform bacteria MCL when E. coli was

detected.

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Surface Water Treatment Rule (SWTR)

Treatment Technique (TT) Violations

These include:

• Exceedance of turbidity standards at the filter confluence point

• Failure to meet disinfection contact time requirements

• Failure to meet disinfection residual standards

A BWA will be required if the violation poses a threat to public health. For example, a filtration plant is overwhelmed by excessive runoff and turbidity levels are in excess of 1.0 NTU for several hours.

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Waterborne Disease Outbreaks

Waterborne Disease Outbreaks can be declared by the Centers for Disease Control, the Department of Community Health, and other public health institutions.

The DEQ will work with the declaring agency and take steps intended to protect public health, one of which may be a BWA.

Cryptosporoidum

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Loss of Pressure

• If a system experiences a loss of pressure, Rule 1207 of Michigan’s Safe Drinking Water Act (Act 399) requires that the system be “disinfected in a manner approved by the department, and compliance with the state drinking water standards shall be demonstrated by additional bacteriological monitoring”.

• Rule 2304 of Act 399 requires immediate notification of the DEQ of an emergency which includes loss of pressure, lack of adequate supply of water, or other condition that poses an imminent hazard or danger to the public health.

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Low Pressure Event Rule 1015(2) of Act 399 requires that a minimum of 35 pounds per square inch (psi) be maintained under normal operating conditions and 20 psi during emergencies such as fire fighting.

• The Boil Water Policy defines a low pressure event as a drop in system pressure below 20 psi and above 5 psi. The decision to issue a BWA will be made on a case by case basis based on factors such as:

• Nature of the service area (residential vs. commercial)

• Duration of the low pressure event

• Disinfection practices of the water system

• Status of the Cross Connection Control Program

• Ability and willingness of the operators to rapidly apply chlorine to the system

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Water Main Break or Repairs A BWA may be issued in response to a water main

break. The decision will be based on the location and severity of the break. Keep in mind:

• The repair should be made under reduced pressure and while water is flowing from the break. If no potential contaminants enter the main during the repair, a BWA will not be necessary.

• If the water main was removed from service for repair is flushed, and disinfected in accordance with AWWA Standard C651 before being placed back into service, a BWA is not required.

• If the water main break resulted is a complete loss of pressure or was contaminated then a BWA for the area impacted will be required.

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Emergency Response Plan

Keep your Emergency Response Plan up to

date and take it seriously. The plan should

be written in a way so that could be

followed by others if you were out of town

and unable to communicate with water

system staff.

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Issuing a BWA

The DEQ has developed a BWA/Public

Notice that includes language required in a

coliform bacteria public notice. This gets

the notice in the hands of the customer

rather than later avoiding annoying or

confusing them with a second notice at a

later date.

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BOIL WATER NOTICE

Water System Name:

Date: We routinely monitor the water for contaminants. Recent tests indicate the presence of coliform bacteria were in the water supply. Coliforms are bacteria which are naturally present in the environment and are used as an indicator that other; potentially-harmful, bacteria may be present. Coliform bacteria were found in more samples than allowed and this is a warning of potential problems. What Should I do? 1. DO NOT DRINK THE WATER WITHOUT BOILING IT FIRST. Bring all water to a boil. Let it boil for one minute, and let it cool before using, or use bottled water. 2. People with severely compromised immune systems, infants and some elderly may be at increased risk. These people should seek advice about drinking water from their doctor. 3. Boiled or bottled water should be used for drinking, making ice, washing dishes, brushing teeth, and food preparation until further notice.

What happened? What is being done?

We are working with drinking water specialists from the Department of Environmental Quality to correct the problem. We may flush and disinfect the system with chlorine.

It may take up to a week to correct the problem.

You will be notified when the advisory is lifted. Please share this information with all the other people who drink this water, especially those who may not have received this notice directly (for example, people in apartments, nursing homes, schools, and businesses). You can do this by posting this notice in a public place or distributing copies by hand or mail.

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Distribution of the BWA/Public

Notice • How and who to notify of a BWA should be included in

your Emergency Response Plan. They include:

• DEQ (if not involved already)

• Local Health Department

• Department of Agriculture (Prepared foods at gas stations)

• Electronic Media

• Critical Customers

• All other customers and consumers of the water (home owners, employees of businesses, and schools)

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Following are suggested additions

to your Emergency Response Plan • Designate an Emergency Response Lead (ER Lead),

and a Spokesperson.

• The ER Lead is the main point of contact and decision-maker during a major event.

• The Spokesperson is the single point of contact for the media and water customers. This allows the ER Lead to focus on responding to the problem. The Spokesperson should be someone who is knowledgeable and credible, and possess good communication skills.

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Helpful Information

• The BWA can be issued for separate isolated pressure districts; however this must be clearly communicated to the public.

• The chlorine smell in water is caused by the chlorine reacting with organic material in the water, including pathogens. So, smelling chlorine during a BWA means that the system is being cleaned out.

• Know the name and cell phone number of the health department Sanitarian assigned to cover the BWA. Questions about food service, etc need to be directed to the Sanitarian.

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Stay Cool and Don’t Panic

Keep good records during a BWA;

who did what and when, chlorine

residuals, sample sites, etc. This

helps reduce liability, is helpful when

filling out the DEQ emergency report,

and when answering questions from

Council members, and others after

the BWA is over.

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When and How to Notify? Rule 402(3) of Act 399 requires that public notice be distributed within 24 hours of learning of the violation in a form and manner reasonably calculated to all persons served.

The form and manner used by the supply are to fit the specific situation, but shall be designed to reach residential, transient, and nontransient users of the supply. To reach all persons served, supplies shall use, at a minimum, 1 or more of the following forms of delivery:

• Appropriate broadcast media, such as radio and television.

• Posting of the notice in conspicuous locations throughout the area served by the supply.

• Hand delivery of the notice to persons served by the system.

• Another delivery method approved, in writing, by the department.

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Rescinding the BWA BWA Type Per DEQ Policy WB-014, the BWA can be rescinded after :

Coliform/E. coli

MCL

Two sample sets collected 24 hours apart are all non-detect

for coliform bacteria. Five samples per set are required, but

can be increased or decreased depending on the situation.

Surface Water

Treatment Rule

(SWTR)

Treatment

Technique (TT)

Violations

After standard treatment has been restored, two sample sets

collected 24 hours apart all non-detect for coliform bacteria.

Five samples per set are required, but can be increased or

decreased depending on the situation.

Waterborne

Disease

Outbreaks

Under the direction of the declaring agency

Loss of

Pressure or Low

Pressure or

Water Main

Breaks or

Repairs

After normal pressure has been restored, the system (or area

impacted) disinfected, and flushed, and a set of five samples

is non-detect for coliform bacteria. If coliform bacteria is

detected in the first round, additional flushing should be

conducted, and then another set of samples collected.

Repeat until a full set of samples in non-detect.

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After the BWA • Be sure that the “all clear” message is transmitted to all

consumers of the water.

• Rule 2304 (2) of Act 399 requires that a written report be filed by the supply within ninety days after an emergency. The DEQ can provide a template.

• If there was an MCL or TT violation be sure to include it in your next CCR.

• Rule 707 (7) of Act 399 requires that a minimum of five routine distribution be collected in the month following a routine distribution coliform-positive sample (BWA or not).

• It is recommended that you have a meeting with your team members to review the boil water event to celebrate successes and to identify what could be done better next time. Use ideas from the meeting in an update of your emergency response plan.

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Conclusion

• A BWA is issued when it is believed that the water system may be at risk of contamination

• Emergency Response Plans should be kept up to date and relied on during a BWA

• The duration of a BWA can be shortened if certain pro-active steps are taken immediately after learning of a coliform-positive sample

• Proper operation, maintenance and record keeping can reduce the risk of contamination and a BWA

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The End

References

• Kirmeyer, G. et al, 1999. Pathogen Intrusion Into the Distribution System. Proc 1999 AWAWA WQTC, Tampa Fla.

• LeChevallier, M.W., 1990. Coliform Regrowth in Drinking Water: A Review. Jour. AWWA, 82: 11: 74

• Miettinen, I. T. et al 1997. Phosphorus and Bacteriological Growth in Drinking Water. Applied & Envir. Microbiol., 63:8:3242.

• Pizzi, N. 1996. Optimizing Distribution System Operations. Opflow, 22:11:1

• White, D. R., & LeChevallier, M.W., 1993. AOC Associated with Oils for Lubricating Well Pumps. Jour. AWWA, 85:8:112.