Chapter 42

DRINKING WATER SAFETY

Contents

Approved by Heather Madison
NEW 07/12

42.1 Policy
42.2 Scope
42.3 Applicability
42.4 Exceptions
42.5 Roles and Responsibilities
42.6 Definitions
42.7 Required Work Processes

Work Process A. General Requirements
Work Process B. Drinking Fountain Testing
Work Process C. Disinfection of Water Systems
Work Process D. Bacteria Testing
Work Process E. Water Dispensers (Bottled Water)

42.8 Source Requirements
42.9 Reference Documents
42.10 Appendices

Appendix A. Disinfecting Domestic Water Systems
Appendix B. Flush Cleaning of Drinking Fountains (Facilities Operating Procedure 057-C)
Appendix C. Sampling Procedure for Metals in Drinking Water
Appendix D. Sampling Procedure for Bacteria in Drinking Water
Appendix E. Disinfection of Water Dispensers (Facilities Operating Procedure 288)

NOTE:
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. . . . . . . . Denotes the beginning of changed text within a section.
. . . . . . . . Denotes the end of changed text within a section.

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42.1 Policy

The Drinking Water Program outlines the management of the drinking-water system at Berkeley Lab. This includes:

42.2 Scope

This policy describes how the drinking-water quality at Berkeley Lab meets all federal, state, and Department of Energy (DOE) guidelines as well as recognized good practice.

42.3 Applicability

Berkeley Lab employees, visitors, affiliates, and subcontractors who either use drinking-water systems or perform work pertaining to drinking-water systems at Berkeley Lab

42.4 Exceptions

None

42.5 Roles and Responsibilities

Role

Responsibilities

Facilities Division — Architecture & Engineering (A&E)

  • Ensures that all written contracts involving repair, modifications, and additions to the drinking-water system are in compliance with the Berkeley Lab Drinking Water Program and that they include disinfection and testing requirements
  • Issues written "stop work" notice to contractors in noncompliance with the Berkeley Lab Drinking Water Program
  • Informs and coordinates with Maintenance & Operations M&O and the Industrial Hygiene Group on all upcoming work involving water systems

Facilities Division — Inspection Group

  • Reviews disinfection procedures with M&O and provides oversight to ensure that contractors are performing work in compliance with the Berkeley Lab Drinking Water Program
  • Issues "stop work" notice to contractors in noncompliance with the Berkeley Lab Drinking Water Program
  • Approves new piping tie-ins to the main water system. Note:  This is a jointly shared responsibility with M&O.
  • Notifies M&O when the contractor is ready to start the disinfection procedure

Facilities Division — Maintenance and Operations (M&O)

  • Completes annual inspection and function-check of all backflow preventers by or under the guidance of a certified employee
  • Provides the Industrial Hygiene Group with samples for coliform and total heterotrophic bacteria samples
  • Audits work performed by contractors to ensure compliance with the Berkeley Lab Drinking Water Program. Informs the Inspection Groups of noncompliance.
  • Disinfects and/or cleans water coolers, drinking fountains, backflow preventers, etc., as needed
  • Supplies potable water to all Berkeley Lab employees. Takes corrective action to resolve issues. Such corrective action may include cleaning and/or replacing drinking fountains, pipes, etc.
  • Approves all tie-ins to the main water system. Note: This is a jointly shared responsibility with the Inspection Group.
  • Ensures there are backflow preventers at all locations where it may be necessary to run hoses from potable water systems into tanks or other receptacles containing hazardous liquids

Environment, Health & Safety Division
Industrial Hygiene Group

  • Provides site-specific guidance and recommendations
  • Approves waivers or exceptions to guidelines in the Berkeley Lab Drinking Water Program, provided such exceptions comply with all applicable regulations and will not compromise water quality
  • Sends water samples to accredited laboratories for analysis
  • Provides M&O with drinking-water sample results and recommendations

All Berkeley Lab Supervisors and Building Managers

Ensure there are backflow preventers at all locations where it may be necessary to run hoses from potable water systems into tanks or other receptacles containing hazardous liquids

42.6 Definitions

Term

Definition

Action Level

Level of concern where a corrective action is taken

Backflow Preventer

A device installed in a water line to prevent water from traveling in the reverse direction

Coliform Bacteria

A type of bacterium whose source is human and animal fecal matter. Although not necessarily disease-causing themselves, coliforms can be indicators of organisms that can cause dysentery, hepatitis, typhoid fever, cholera, etc.

Contractor

A contractor employed by Berkeley Lab. Both the contractor and the work crew will be non-Berkeley Lab employees.

Disinfection

Sanitizing a system or its components in such a way as to kill any coliform bacteria that may be present

Drinking Water Fountain

A fountain piped to a building's domestic water supply that may be capable of cooling and/or heating the water

LCW

Low-conductivity water. A type of nonpotable, de-ionized water that has many of the ions removed, typically by ion exchange resins. Commonly used for cooling equipment used for experimental purposes. Some buildings have LCW water piped from a central facility.

Nonpotable Water

Water not approved for drinking, also called Industrial Water. Examples are fire sprinkler systems, laboratory sinks, LCW, cooling water, heating water.

Potable Water

Water approved for drinking that meets all federal and state guidelines and standards

Total Heterotrophic Plate Count

A test that measures total bacteria in a water sample. Although there is no drinking-water standard for total bacteria, a test result greater than 500 colony-forming units per milliliter (cfu/ml) indicates that coliform test results may be invalid because of masking.

Water Dispensers (portable)

Water supplied in portable containers (bottled water) to locations that do not have piped water (e.g., guard shacks, trailers) or where the drinking water is temporarily out of service

PPE

Personal Protective Equipment.  Safety equipment worn by employees; may include safety glasses, respirators, coveralls, gloves, etc.

42.7 Required Work Processes

Work Process A. General Requirements

Most drinking-water hazards fall within a few common areas.

Some drinking-fountain units and copper-pipe dead legs (dead-end pipes) that are not flushed or used frequently can produce copper contamination in excess of allowable levels. Rust from iron piping is observed in some older facilities. Occasionally, other various off-colors and tastes are reported.

When designing/installing potable-water systems that supply chemical-containing systems, it is important to install adequate backflow devices that prevent back-siphoning of toxic materials into the potable water system. Although Berkeley Lab has completed a major project to upgrade all systems sitewide, system users must still remain aware and ensure that all new equipment is provided with adequate backflow-prevention devices. Hoses extending into sinks are a common potential problem if backflow devices are not installed.

Backflow-prevention devices must be installed on all drinking-water lines where they are connected to industrial (e.g., low-conductivity water [LCW], fire sprinkler) or other nonpotable-water systems. Backflow preventers must also be installed in locations where it may be necessary to temporarily run hoses from potable-water sources to tanks or other receptacles containing hazardous liquids. Direct connections of drinking-water supplies to receptacles containing hazardous materials is not allowed.

Backflow preventers must be inspected and tested annually by or under the guidance of certified employees in M&O.

Work Process B. Drinking Fountain Testing

All drinking-water fountains must have baseline testing for lead and copper concentrations in the water. If the water is found to exceed the drinking-water standard, the fountain will be tagged "Do Not Drink" and disconnected from the building. The water-supply line for the drinking fountain will be tested to determine if the problem is with the fountain or the building. If the fountain is the problem, it will be removed, cleaned (see Appendix B), re-installed by M&O, and resampled. If it again exceeds the drinking-water standard for copper or lead, it will be replaced. If the building is the problem, all fixtures must be labeled as nonpotable water until the problem can be corrected. Refer to Appendix C for the metals- sampling procedure.

Work Process C. Disinfection of Water Systems

Water systems must be isolated from the main water system and not put into service (excluding small jobs, see below) as potable water until the water is confirmed free of coliform bacteria. In certain instances, after approval by Facilities and the Industrial Hygiene Group, the water may be used temporarily for nonpotable purposes, such as toilets or sinks, if  there is a backflow preventer between the new system and the main line and the fixtures in temporary use are labeled "nonpotable." In all cases, the new water system must be thoroughly flushed (minimum of 10 minutes) before the system is released for service.

  1. Underground piping systems. These must be disinfected with an aqueous solution of sodium hypochlorite or calcium hypochlorite having at least 5.25% available chlorine. The use of granular or tablet hypochlorite compounds is prohibited unless specifically approved by the Industrial Hygiene Group. See Appendix A for procedure.
  2. Aboveground piping systems.These need not be disinfected as outlined above, though in all cases they must remain isolated from the main water system until coliform bacteria test results confirm the bacterium is absent. If coliform bacteria are present in the piping system, it must be disinfected following the Appendix A procedure.
  3. Individual parts, fixtures, isolation valves, pipes less than 5 feet long. These can be swabbed with full-strength bleach (5.25%) or soaked for at least 30 minutes in a 500 ppm chlorine solution. The 500 ppm solution can be made by adding one part 5.25% bleach (stores bleach) to 100 parts drinking water. For example, 10 ml of stores bleach can be added to 1 liter of drinking water. Parts should then be thoroughly rinsed before putting into service. A coliform bacteria test is not necessary for this small-scale work.

Work Process D. Bacteria Testing

  1. New piping installations. In drinking-water systems, new piping installations must be tested for coliform bacteria before they are approved for use for potable water unless the work is of a small scale, and provided the parts are individually disinfected. Examples of small-scale work are less than 5 feet of pipe; and  replacement and/or installation of a sink, drinking fountain, eyewash, backflow preventer, or isolation valve. Samples must be analyzed by the membrane-filtration method after a 24-hour incubation period in the pipes with chlorine-free water. See Appendix D for details of the sampling procedure. Water-sample analysis must indicate that the water is free (i.e., none detected) of coliform bacteria. If it isn't, the pipingmust be disinfected again.
  2. Routine monitoring. The drinking-water system for each building must be tested annually for coliform bacteria.

Work Process E. Water Dispensers (Bottled Water)

It is recommended that these dispensers be cleaned at least every six months by M&O or by the user group. See Appendix E for procedure.

42.8 Source Requirements

42.9 Reference Documents

Standard Methods for the Examination of Water and Wastewater, 18th or later edition

42.10 Appendices

Appendix A. Disinfecting Domestic Water Systems

  1. General Discussion. The American Water Works Association (AWWA) Standard C651-99, Disinfecting Water Mains, must be used as the standard method for disinfecting new water-main installations and disinfection following modification of existing systems. The specific procedure to be used is the continuous-feed method of chlorination. Other sections of the standard disinfection procedure are used as a reference for work practices and procedures in system modifications of any size. This Appendix contains a summary of the AWWA continuous-feed chlorination system of disinfection.
  2. Preliminary Preparations
    1. Provide and install a ¾-inch service cock or valve within 3 feet of the supply main in order to introduce the disinfecting agent into the lines.
    2. Provide and install a ¾-inch service cock or valve at all dead ends in the line or in connections to the line to properly drain and vent the line to assure that all parts and components of the line are contacted by the disinfecting agent.
    3. When temporarily connecting a new water system to the main line (e.g., supply water for pressure testing, chlorination, etc.), provide and install a flexible hose connection with a backflow prevention assembly (BFP). (Note: Hard pipe connections are permitted only after the new water system has been tested and approved. Connections to the main water system and exceptions to these procedures must be pre-approved by O&M or the Inspection groups.)
    4. After the final pressure-testing of the new line and prior to the draining of this line for disinfection, the line must be thoroughly flushed until the water leaving the line is clear. This must be done by fully opening all fixtures, outlets, and service cocks or valves at all dead ends. The flushing velocity in the main must not be less than 2.5 ft/s. Flushing is not a substitute for preventive measures during construction, such as keeping the piping free of contaminants.
  3. Disinfecting Procedures
    1. These procedures must be carried out in the presence of the Project Inspector from the Berkeley Lab Facilities Division, Design and Construction Department.
    2. Drain the entire part of the domestic water system that is to be tested, including all fire lines connected to it.
    3. Post suitable warning signs at each outlet: "Warning — Do Not Use — Water System Being Chlorinated."
    4. Close those valves necessary to isolate that section of the water system to be tested. Open all fixtures and outlets and all service valves or cocks at dead ends in this section of the line. Open the supply valve sufficiently to allow a reduced flow through this section of the line while simultaneously injecting the disinfectant solution into the system through the ¾-inch service cock near the supply valve. This injection must be made using a pump or pressure device at slow, continuous rate. The injection must be continued until the water at every outlet shows a free chlorine concentration of at least 25 ppm, as determined by chlorine test papers.
    5. Again isolate the section of the water system being disinfected by closing all outlets and valves, including the supply valves in the main and the injection service cock. Allow the chlorinated water to stand in this section of the water system.
    6. After 24 hours, the chlorinated water standing in the line must again be sampled and tested for chlorine concentration. The water should show a chlorine concentration of not less than 10 ppm, as determined by free chlorine test papers. If the water shows less than 10 ppm chlorine, the injection procedure must be repeated and the water allowed to stand for another 24 hours. Retesting of the water at the end of this period must show a minimum free chlorine concentration of at least 50 ppm, as determined by the chlorine test papers.
    7. When the residual chlorine requirements have been fulfilled, the part of the water system being disinfected must be drained and flushed until the chlorine concentration of the discharged water has been reduced to an amount equivalent to the level normally present in the water supplied to the area, or less than 1 ppm. This part of the system must again be isolated by valving off.
    8. After checking that the residual chlorine concentration is not greater 1 ppm using test strips, O&M will take water samples after a 24-hour incubation period at predetermined locations of the isolated system. The sampling points will be chosen so as to provide accurate information regarding the bacteriological quality of the water. The samples will be analyzed by a California Department of Health Services accredited laboratory selected by a Berkeley Lab Industrial Hygienist. The laboratory must be accredited for bacteriological analysis as described by the Standard Methods for the Examination of Water and Wastewater, 18th or later edition. Before putting the system into service, the results of these tests must show the water to be completely free (i.e., <1 or none detected) of coliform organisms after a 24-hour incubation period.
    9. If the results of the bacteriological tests do not meet the standard specified above, the disinfection procedure must be repeated until this standard is satisfied.
    10. Tie-in fittings to be placed in existing mains must be sterilized either by immersing in a chlorine solution of 500 ppm for 15 minutes or by swabbing with a 5% hypochlorite solution (household bleach).
    11. On systems in which a fire sprinkler riser is to be directly connected to an existing underground link that has been previously sterilized and terminates above ground, the double check valves, test cocks, and all fittings between the check valves and the termination of the underground line should be immersed in a 500 ppm chlorine solution for one hour prior to assembly. The termination of the underground line is not to be left uncovered.
  4. Approval. When all above procedures have been properly carried out, and when the water sample test results comply with the limits specified in Section C, Nos. 7 and 8, above, the section of water line being disinfected will be approved for potable water use. A Berkeley Lab Industrial Hygienist must furnish such approval in written form to the Project Manager.

Reference: AWWA Standard, Disinfecting Water Mains, ANSI/AWWA C651-99.


Appendix B. Flush Cleaning of Drinking Fountains (Facilities Operating Procedure 057-C)

1. Application. Removal of mineral deposits from the drinking fountain piping system
2. Special Instructions

  1. Citric acid is used to remove mineral deposits from interior piping. Citric acid is a mild acid, and is hazardous if not handled properly. Follow the product Material Safety Data Sheet (MSDS).
  2. Special equipment needed: eye protection, rubber gloves, one 5-gallon container, one 5-gallon plastic container, citric acid, baking soda (sodium bicarbonate), hand tools.
  3. This operation applies to plant maintenance technicians trained in the performance of drinking-fountain procedures.

3. Work Steps

  1. Drinking fountains to be cleaned are removed by plumbers and brought to Building 76. Fountains are cleaned when a report of restricted water flow is received.
  2. Connect hoses to the drinking fountain and cleaning unit. Remove the fountain head and any strainers. The cleaning unit (cart) is stored in the patio area outside the west end of Building 76.
  3. Place the plastic tray on plywood on pallet.  Pick up the pallet and tray with a hand truck and place it under Crane CR-23-76. Lift the cleaning unit into the plastic tray. The plastic tray is required for double containment during cleaning. It’s kept in the mezzanine above the Building 76 conference room.
  4. Add water to the cleaning unit and operate the unit. Check the cleaning unit for leaks. Use the handtruck under the pallet to move the assembly outside to the sump area in case of a leak during any part of the cleaning process.
  5. Drain the water from the cleaning unit.
  6. Put on rubber gloves and eye protection.
  7. Mix 8 ounces of citric acid and 3 gallons of 160° water in the cleaning unit, and flush until clean. Check on the operation periodically.
  8. Drain the solution into a clean 5-gallon plastic container. Label and save the container for analysis. Contact the Operations Waste Accumulation Coordinator for disposition of the solution.
  9. Mix 8 ounces of baking soda and 3 gallons of 160° water in the cleaning unit, and flush for 15 minutes.
  10. Drain the solution into a clean 5-gallon container. Label and save the container for analysis. Contact the Operations Hazardous Waste Coordinator for disposition of the solution.
  11. Flush the fountain with city water for 15 minutes or until clear. Move the assembly outside to the sump area using the handtruck. Drain the water. This water does not need to be saved.
  12. Clean the exterior of the fountain and clean the condenser of dust, etc.
  13. Lock out and tag out the valves and power disconnect that you have secured.

Appendix C. Sampling Procedure for Metals in Drinking Water

1. General Discussion

  1. Drinking water may exceed drinking-water standards for metal content for a variety of reasons, such as stagnation, improper installation (electrolysis), improper manufacture, etc. High metal content in the water can impart a metallic taste to the water, and may exceed primary drinking-water health standards. For copper-pipe installations, analyze for copper and lead (in the solder); for galvanized pipe, analyze for iron and zinc. Historically, most problems are from drinking fountains, where a copper and lead analysis would be applicable.
  2. The purpose of this procedure is to provide directions for sampling metals in drinking water.

2. Preliminary Preparations

  1. The analytical laboratory pickup does not need to be the same day the samples are taken. However the samples should be picked up as soon as possible. Arrangements should be made with the laboratory in advance for timely pickup.
  2. Equipment required: 1-liter new plastic container with HNO3 (obtained from the analytical lab), safety glasses, and gloves.

3. Sampling Procedures

  1. Metals samples should be first draw. This is performed first thing in the morning, when water has been standing in the lines overnight. The water must have been standing a minimum of 6 hours, and there is no outer limit (maximum) on the standing time.
  2. For first-draw samples, do not let the water run before sampling.
  3. Position the sample bottle under the fixture, and turn on the water.
  4. Turn the water off just before the sample bottle is full. Do not allow the bottle to overflow. This might allow loss of nitric acid from the bottle.
  5. Refrigerate the samples after collection.
  6. Arrange with the Laboratory’s analytical laboratory for sample pickup.

References:

Appendix D. Sampling Procedure for Bacteria in Drinking Water

1. General Discussion

  1. Drinking water may exceed drinking-water standards for bacterial content for a variety of reasons, such as a pipe break, siphoning action, installation of contaminated pipes and fixtures, repair work that allows soil or trench water into the system, etc. Water contaminated with bacteria can cause dysentery, gastroenteric infections, etc. Coliform is the most common type of bacterium sampled for, and must be absent, or none detected. Coliform is a type of bacterium common in soil, plants, and animals. Fecal coliform is a subgroup whose source is fecal matter from warm-blooded animals. Although not necessarily disease-causing themselves, coliform and fecal coliform bacteria can indicate contamination.
  2. Fecal material may contain disease-causing organisms, such as cholera, hepatitis, etc. The presence of any coliform, including fecal coliform bacteria, is unacceptable. While analysis may distinguish between total coliform and fecal coliform bacteria, the Berkeley Lab Drinking Water Program requires that water be free of all coliform bacteria. Therefore the bacteriological testing required is for the Presence/Absence of coliform bacteria.

2. Preliminary Preparations

  1. The analytical laboratory must pick up the samples the same day they are taken. Arrangements should be made with the analytical laboratory in advance, for timely pickup.
  2. Equipment required: 100 ml new plastic container (obtained from the analytical lab), safety glasses, and gloves.

3. Sampling Procedures

Reference:
Standard Methods for the Examination of Water and Wastewater (SM), American Public Health Association/AWWA/Water Environment Federation, 18th edition

Appendix E. Disinfection of Water Dispensers (Facilities Operating Procedure 288)

  1. Application. This procedure covers disinfection of water dispensers used for bottled water. Improper storage of bottled water and inadequate disinfection of water dispensers can result in significant algae growth and undesirable levels of bacteria. Although this is not a health hazard, excessive algae and bacteria can result in poor taste, odor problems, and an undesirable appearance. For this reason, it is recommended that bottled water coolers be cleaned at least every 6 months, though low usage may require a more frequent cleaning schedule.
  2. Special Instructions
    1. Since exposure to direct sunlight enhances the growth of the algae and bacteria, drinking-water bottles should be stored in a cool, dark place.
    2. Equipment required: 14-quart plastic bucket, cellulose sponge, ½-inch test-tube brush, gloves (latex, rubber, nitrile, or neoprene), 5.25% liquid bleach (household bleach), plug for hot-water tank (if required).
  3. Work Steps
    1. Unplug the dispenser.
    2. Remove the water bottle, then drain the water remaining in the dispenser into the bucket.
    3. Remove and empty the spill reservoir located below the spigots.
    4. Move the dispenser adjacent to a sink (if you’re not already adjacent to a sink). The sanitizing solution and rinse water used in this procedure can be drained into the sink.
    5. If you are disinfecting a hot-water model, plug the inlet to the hot water tank. DO NOT allow the sanitizing solution to enter the hot water tank.
    6. Wearing gloves, mix 5 ml of bleach with 4 liters of tap water (½ teaspoon of bleach to 1 gallon of water) in the bucket. DO NOT use a stronger sanitizing solution.
    7. Wash the spill reservoir, cooling tank, and baffle with the bleach solution, wiping all accessible surfaces with the sponge.
    8. Use the test-tube brush to clean inaccessible areas such as inside the spigots.
    9. Fill the dispenser reservoir with the sanitizing solution, let set for about three minutes, and then drain the sanitizing solution through the spigot. A minimum contact time of three minutes and a maximum contact time of five minutes is required.
    10. Rinse parts thoroughly with tap water by filling the dispenser reservoir completely with tap water, then drain. Repeat this fill-and-drain at least three times.
    11. Remove the plug from the hot-water reservoir (if one is installed), and rinse with tap water.
    12. Return to the original location (if moved), install the water bottle, and plug the unit in.
    13. Attach a "Facilities Dept. Work Notice" tag (shown below) to the dispenser, with the next cleaning due date noted on the bottom.

 

 

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