In April and September 1993, CDC convened two advisory workshops to review and revise fluoridation recommendations. Since 1979, CDC has developed guidelines and/or recommendations for managers of fluoridated public water systems. This report summarizes the results of these two workshops and consolidates and updates CDC's previous recommendations. Implementation of these recommendations should contribute to the achievement of continuous levels of optimally fluoridated drinking water for the U.S. population, minimize potential fluoride overfeeds (i.e., any fluoride level that is greater than the recommended control range of the water system), and contribute to the safe operation of all fluoridated water systems. The report delineates specific recommendations related to the engineering aspects of water fluoridation, including administration, monitoring and surveillance, technical requirements, and safety procedures. The recommendations address water fluoridation for both community public water supply systems and school public water supply systems.# INTRODUCTION
Water fluoridation is the deliberate addition of the natural trace element fluorine (in the ionic form as fluoride) into drinking water in accordance with scientific and dental guidelines (1)(2)(3)(4)(5)(6)(7)(8)(9). Fluoride is present in small yet varying amounts in almost all soil, water supplies, plants, and animals and, thus, is a normal constituent of all diets (10 ). In mammals, the highest concentrations are found in the bones and teeth.
Since 1945, many studies have demonstrated the oral health benefits of fluorides and fluoridation. In 1945 and 1947, data from four studies (Grand Rapids, Michigan; Newburgh, New York; Brantford, Ontario ; and Evanston, Illinois) demonstrated the oral health benefits of fluoridated water in several communities and established water fluoridation as a practical, effective public health measure that would prevent dental caries (11)(12)(13)(14). Data have consistently indicated that fluoridation is safe and is the most cost-effective and practical means for reducing the incidence of dental caries (tooth decay) in a community (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28). However, additional studies have demonstrated that the oral health benefits are reduced if the optimal level of fluoride is not maintained (29)(30). In the past, maintaining the optimal level without active monitoring/surveillance programs has been difficult. In the 1970s, approximately half of the systems presumed to be fluoridated were not consistently maintaining the optimal fluoride concentrations.
Since the late 1970s, CDC has developed technical and administrative guidelines and/or recommendations for correcting inconsistencies in fluoridated public water supply systems (CDC, unpublished data; . In April and September of 1993, CDC convened two advisory workshops to review and revise fluoridation guidelines. Participants included 11 technical experts from state agencies and the Indian Health Service. Additional comments were obtained from state dental officials, state drinking water personnel, and others (e.g., schools of public health, dental societies, and engineers from private industry). The intent of these recommendations is to provide guidance to federal, state, and local officials involved in the engineering or administrative aspects of water fluoridation, which should help ensure that fluoridated water systems are providing optimal fluoride levels.
This report provides information from earlier studies linking fluoridation with the reduction of dental caries, summarizes the conclusions of the workshops, provides recommendations for fluoridation of both community and school public water supplies, and consolidates previous recommendations. These recommendations are written with the assumption that the reader either has an engineering background or at least is familiar with basic water supply engineering principles. As an aid to readers, a glossary of technical terms is included.

# BACKGROUND History of Water Fluoridation
The capacity of waterborne fluoride to prevent tooth decay was recognized in the early 1900s in Colorado Springs, Colorado, when a dentist noted that many of his patients' teeth exhibited tooth discoloration (i.e., "Colorado Brown Stain"). Because that condition had not been described previously in the scientific literature, he initiated research about the condition and found that Colorado Brown Stain-now termed fluorosis (mottled enamel)-was prevalent throughout the surrounding El Paso County. The dentist described fluorosis and made recommendations on how to prevent its occurrence (34,35 ). Other dentists and researchers also had noted the occurrence of fluorosis and theorized that fluoride in the water might be associated with the condition. They also noted that persons who had fluorosis had almost no dental caries (36 ) The dentist in Colorado subsequently collaborated with the U.S. Public Health Service to determine if fluoride could be added to the drinking water to prevent cavities (2,37 ). Further studies were conducted that confirmed the cause-andeffect relation between fluoridation and the reduction of dental caries (1,3,6,38,39 ).

# National, State, and Local Fluoride Guidelines
A public water system can be owned by the municipality that it serves, or it may be corporately owned. A public water system is not defined by its ownership. To be considered a public water system, the system must have 15 service connections or must regularly serve an average of 25 persons for 60 days per year. Public water systems do not necessarily follow city, county, or even state boundaries. For example, a large municipality may be served by one water system or by multiple water systems; a public water system may serve several municipalities. Individual states' regulations and/or guidelines for respective water systems range from specific to general. The recommendations and guidelines for water fluoridation must be sufficiently general to allow for individual states' variations in nomenclature and organization.
Schools that have individual water systems, which are considered public water systems, are subject to all the rules that apply to public water systems. However, because of limits on use and the size of these systems, they have been included in a subcategory of public water systems referred to as nontransient, noncommunity public water systems. Special recommendations and guidelines that apply to school public water systems are included in this report.
Although no national regulations or laws govern water fluoridation, many federal agencies concur that water fluoridation is beneficial to public health (M. Cook, personal communication; 40 ). The Environmental Protection Agency (EPA), through the Safe Drinking Water Act of 1986, has established national requirements for public water systems but not for adjusted water fluoridation. EPA also has established a maximum concentration level for natural fluoride in drinking water. If the fluoride content in drinking water exceeds this level, it must be removed.*

# RECOMMENDATIONS FOR FLUORIDATED COMMUNITY PUBLIC WATER SUPPLY SYSTEMS I. Administration

# B. System Reporting Requirements
Whenever the fluoride content of drinking water is adjusted, a person should be designated to report daily fluoride test results to the appropriate state agency. These reports should be submitted each month. a. An evaluation of the fluoride testing equipment;
b. An inspection of the chemical (fluoride) storage area;
c. An inspection of the operation and maintenance manuals; d. A check to ensure that only state-approved backflow preventers and antisiphon devices (as well as testing procedures for such equipment) are being used;
e. An evaluation of the on-site emergency plans (stipulated actions in case of overfeed and public-notification procedures to be followed) (Table 1);
f. An inspection of the plant's security (e.g., placement of appropriate signs and fences and preventing entrance by unauthorized persons); and
g. An inspection of the on-site safety equipment available to the operator.

# F. Actions in Case of Overfeed
State personnel must provide each water plant with procedures to follow in the event of an overfeed. These operating procedures should address the following:

# II. Monitoring and Surveillance
A. Water system personnel must monitor daily fluoride levels in the water distribution system. Samples that will reflect the actual level of fluoride in the water system should be taken at points throughout the water system. The sites where samples are taken should be rotated daily.

# B.
At least once each month, water system personnel should divide one sample and have one portion analyzed for fluoride by water system personnel and the other portion analyzed by either the state laboratory or a state-approved laboratory.
C. Each water system must send operational reports to the state at least monthly. The report must include:
1. The amount and type of chemicals fed and the total number of gallons of water treated per day;
2. The results of daily monitoring for fluoride in the water distribution system; and
3. The results of monthly split sample(s).

# D.
The calculated dosage should be cross-checked against the reported fluoride levels to spot chronic nonoptimal operation. E. The system's raw water source (i.e., water that has not been treated) should be analyzed annually for fluoride by either the state laboratory or a stateapproved laboratory, or in accordance with state regulations.

# F.
If the optimal fluoride level in a community public water supply system has not been set by the state, optimal fluoride levels should be established (Table 2). (State regulations supersede recommended optimal fluoride levels contained in this report.)
G. All state laboratories should participate in CDC's Fluoride Proficiency Testing Program to ensure the accuracy of their fluoride testing program.

# III. Technical Requirements
A. General 1. The fluoride feed system must be installed so that it cannot operate unless water is being produced (interlocked). For example, the metering pump must be wired electrically in series with the main well pump or the service pump. If a gravity flow situation exits, a flow switch or pressure device should be installed. The interlock might not be required for water systems that have an operator present 24 hours a day.
2. When the fluoridation system is connected electrically to the well pump, it must be made physically impossible to plug the fluoride metering pump into any continuously active ("hot") electrical outlet. The pump should be plugged only into the circuit containing the interlock protection. One method of ensuring interlock protection is to install on the metering pump a special, clearly labeled plug that is compatible only with a special outlet on the appropriate electrical circuit. Another method of providing interlock protection is to wire the metering pump directly into the electrical circuit that is tied electrically to the well pump or service pump, so that such hard wiring can only be changed by deliberate action.
3. A secondary flow-based control device (e.g., a flow switch or a pressure switch) should be provided as back-up protection in water systems that serve populations of <500 persons.
The fluoride injection point should be located where all the water to be treated passes; however, fluoride should not be injected at sites where substantial losses of fluoride can occur (e.g., the rapid-mix chemical basin). In a surface-water treatment plant, the ideal location for injecting fluoride is the rapid sand filter effluent line going into the clearwell. 5. The fluoride injection point in a water line should be located in the lower one third of the pipe, and the end of the injection line should extend into the pipe approximately one third of the pipe's diameter (31,32 ). 6. A corporation stop valve should be used in the line at the fluoride injection point when injecting fluoride under pressure. A safety chain must always be installed in the assembly at the fluoride injection point to protect the water plant operator if a corporation stop valve assembly is used.
7. Two diaphragm-type, antisiphon devices must be installed in the fluoride feed line when a metering pump is used. The antisiphon device should have a diaphragm that is spring-loaded in the closed position. These devices should be located at the fluoride injection point and at the metering pump head on the discharge side. The antisiphon device on the head of the metering pump should be selected so that it will provide the necessary back pressure required by the manufacturer of the metering pump.
8. All antisiphon devices must be dismantled and visually inspected at least once a year. Schedules of repairs or replacements should be based on the manufacturer's recommendations. Vacuum testing for all antisiphon devices should be done semiannually. Operation of a fluoridation system without a functional antisiphon device can lead to an overfeed that exceeds 4 mg/L.
The fluoride metering pump should be located on a shelf not more than 4 feet (1.2 m) higher than the lowest normal level of liquid in the carboy, day tank, or solution container. A flooded suction line is not recommended in water fluoridation.
10. For greatest accuracy, metering pumps should be sized to feed fluoride near the midpoint of their range. Pumps should always operate between 30%-70% of capacity. Metering pumps that do not meet design specifications should not be installed. Oversized metering pumps should not be used because serious overfeeds (i.e., an overfeed that exceeds 4 mg/L) can occur if they are set too high. Conversely, undersized metering pumps can cause erratic fluoride levels.
11. The priming switch on the metering pump should be spring-loaded to prevent the pump from being started erroneously with the switch in the priming position.
12. An in-line mixer or a small mixing tank should be installed in the finished water line exiting from the water plant if the first customer is 100 feet (30.5 m) from the fluoride injection point and if there is no storage tank located in the line before the water reaches the customer. The minimum distance is 100 feet, assuming there are typical valves and bends in the water line that allow for adequate mixing.
13. Flow meter-paced systems should not be installed unless the rate of water flow past the point of fluoride injection varies by more than 20%.
14. A master meter on the main water service line must be provided so that calculations can be made to confirm that the proper amounts of fluoride solution are being fed.
15. The fluoride feed line(s) should be either color coded, when practical, or clearly identified by some other means. Color coding helps prevent possible errors when taking samples or performing maintenance. The pipes for all fluoride feed lines should be painted light blue with red bands. The word "fluoride" and the direction of the flow should be printed on the pipe (42 ).
16. Fluoride feed equipment, controls, safety equipment, accessory equipment, and other appurtenances must be inspected annually.

# B. Sodium Fluoride Saturator Systems
1. The minimum depth of sodium fluoride in a saturator should be 12 inches (30.5 cm). This depth should be marked on the outside of the saturator tank. The saturator should never be filled so high that the undissolved chemical is drawn into the pump suction line.
2. Only granular sodium fluoride should be used in saturators, because both powdered and very fine sodium fluoride tend to cause plugging in the saturator.
3. The water used for sodium fluoride saturators should be softened whenever the hardness exceeds 50 parts per million (ppm). Only the water used for solution preparation (i.e., the make-up water) needs to be softened.
A flow restrictor with a maximum flow of 2 gallons (7.6 L) per minute should be installed on all upflow saturators.
5. In the event of a plant shutdown, the make-up water solenoid valve should be physically disconnected from the electrical service.
6. For systems that use 10 gallons (38 L) of saturator solution per day, operators should consider using an upflow saturator that is manually filled with water.
7. In an upflow saturator, either an atmospheric vacuum breaker must be installed or a backflow prevention device must be provided in accordance with state or local requirements. The vacuum breaker must be installed according to the manufacturer's recommendations.
8. A sediment filter (20 mesh) should be installed in the water make-up line going to the sodium fluoride saturators. The filter should be placed between the softener and the water meter.
A water meter must be provided on the make-up water line for the saturator so that calculations can be made to confirm that the proper amounts of fluoride solution are being fed. This meter and the master meter should be read daily and the results recorded.
10. Unsaturated (batch-mixed) sodium fluoride solution should not be used in water fluoridation.

# C. Fluorosilicic Acid Systems
1. To reduce the hazard to the water plant operator, fluorosilicic acid (hydrofluosilicic acid) must not be diluted. Small metering pumps are available that will permit the use of fluorosilicic acid for water plants of any size.
2. No more than a 7-day supply of fluorosilicic acid should be connected at any time to the suction side of the chemical feed pump. All bulk storage tanks with more than a 7-day supply must have a day tank. A day tank should only contain a small amount of acid, usually a 1-or 2-day supply.
3. Day tanks or direct acid-feed carboys/drums should be located on scales; daily weights should be measured and recorded. Volumetric measurements, such as marking the side of the day tank, are not adequate for monitoring acid feed systems.
4. Carboys, day tanks, or inside bulk storage tanks containing fluorosilicic acid must be completely sealed and vented to the outside.
5. Fluorosilicic acid should be stored in bulk, if economically feasible.
6. Bulk storage tanks must be provided with secondary containment (i.e., berms) in accordance with state/local codes or ordinances.

# D. Dry Fluoride Feed Systems
1. A solution tank that has a dry feeder (both volumetric and gravimetric) must be provided.
2. Solution tanks should be sized according to CDC guidelines (31 ).
3. A mechanical mixer should be used in every solution tank of a dry feeder when sodium fluorosilicate (i.e., silicofluoride) is used.
4. Scales must be provided for weighing the amount of chemicals used in the dry feeder.

# E. Testing Equipment
1. Operators of surface water plants should use the ion electrode method of fluoride analysis because chemicals (e.g., alum) used in a surface water plant will cause fluctuating interferences in the colorimetric method (SPADNS) of fluoride analysis (47 ).
A magnetic stirrer should be used in conjunction with the ion electrode method of fluoride analysis.
3. The colorimetric method (SPADNS) of fluoride analysis can be used where no interference occurs or where the interferences are consistent (e.g., from iron, chloride, phosphate, sulfate, or color). The final fluoride test result can be adjusted for these interferences. State laboratory personnel, the state fluoridation specialist, and the water plant operator should reconcile the interferences and make the appropriate adjustment.
4. Distillation is not needed when the colorimetric method (SPADNS) of fluoride analysis is used for testing daily fluoride levels.

# IV. Safety Procedures
Fluoride remains a safe compound when maintained at the optimal level in water supplied to the distribution system; however, an operator might be exposed to excessive levels if proper procedures are not followed or if equipment malfunctions. Thus, the use of personal protective equipment (PPE) is required when fluoride compounds are handled or when maintenance on fluoridation equipment is performed. The employer should develop a written program regarding the use of PPE. The water supply industry has a high incidence of unintentional injuries compared with other industries in the United States; therefore, safety procedures should be followed (48 ).

# A. Operator Safety
1. Fluorosilicic acid a. The operator should wear the following PPE:
- Gauntlet neoprene gloves with cuffs, which should be a minimum length of 12 inches (30.5 cm);
- Full face shield and splash-proof safety goggles; and - Heavy-duty, acid-proof neoprene apron or acid-proof clothing and shoes.
b. A safety shower and an eye wash station must be available and easily accessible. - Splash-proof safety goggles;
- Gauntlet neoprene gloves, which should be a minimum length of 12 inches (30.5 cm); and
- Heavy-duty, acid-proof neoprene apron.
b. An eye wash station should be available and easily accessible.

# Exposure to fluoride chemicals
If the operator gets either wet or dry chemicals on the skin, he or she should thoroughly wash the contaminated skin area immediately. If the operator's clothing is contaminated with a wet chemical, he or she should remove the wet contaminated clothing immediately. If the operator's clothing becomes contaminated with dry chemicals, he or she should change work clothing daily no later than the close of the work day (51).

# B. Recommended Emergency Procedures For Fluoride Overfeeds
1. Fluoride overfeeds a. When a community fluoridates its drinking water, a potential exists for a fluoride overfeed. Most overfeeds do not pose an immediate health risk; however, some fluoride levels can be high enough to cause immediate health problems. All overfeeds should be corrected immediately because some have the potential to cause serious long-term health effects (52)(53)(54)(55).
b. Specific actions should be taken when equipment malfunctions or an adverse event occurs in a community public water supply system that causes a fluoride chemical overfeed (Table 1) (33 ).
c. When a fluoride test result is at or near the top end of the analyzer scale, the water sample must be diluted and retested to ensure that high fluoride levels are accurately measured.

# Ingested fluoride overdose
Persons who ingest dry fluoride chemicals and fluorosilicic acid should receive emergency treatment (Tables 3 and 4) (10,56-62 ).

# RECOMMENDATIONS FOR FLUORIDATED SCHOOL PUBLIC WATER SUPPLY SYSTEMS I. Administration
School water fluoridation is recommended only when the school has its own source of water and is not connected to a community water system. Each state is responsible for determining whether school water fluoridation is desirable and for effecting a written agreement between the state and appropriate school officials. A school water fluoridation program must not be started unless resources are available at the state level to undertake operational and maintenance responsibilities. For example, one full-time school technician should be assigned to every 25-30 schools. The following recommendations should be implemented for a school water fluoridation program:
A. The state must take the primary responsibility for operating and maintaining school fluoridation equipment. School personnel should be responsible only

# II. Monitoring and Surveillance
A. For each school that has a fluoridated water system, a sample of the drinking water must be taken and analyzed for fluoride content before the beginning of each school day. Samples may be taken by appropriate school personnel. This sampling will not prevent fluoride overfeeds but will prevent consumption of high levels of fluoride.
B. School personnel must divide at least one sample per week, with one portion analyzed for fluoride at the school and the other portion analyzed at the state laboratory. The weekly state test results should be compared with test results obtained at the school to ensure that school personnel are using the proper analytic techniques and that their daily samples are being tested accurately for fluoride.
C. Optimal fluoride levels in a school water system should be established by the state (Table 5). (State regulations supersede recommendations provided in this report.)

# III. Technical Requirements
A. General 1. School water fluoridation systems should be installed only where the water is supplied by a well pump with a uniform flow because varying flow rates can cause problems in consistently maintaining optimal fluoride levels (31 ).
2. All school water fluoridation systems should be built with a bypass arrangement so that the fluoridation equipment can be isolated during service and inspection periods without shutting off the school water supply. Most states use a pipe loop, with gate valves isolating such devices as the injection point, meters, strainers, check valves, make-up water, and take-off fittings.
3. Fluoridation equipment should be placed in an area that is secure from tampering and vandalism.  4. A routine maintenance schedule should be established. Items to be checked include pump diaphragm, check valve, Y-strainers or sediment filters, injection points (for clogging), flow switch contacts and paddles, saturator tank (for cleaning), pressure switch, solenoid valve, float switch, and foot valve.
5. All hose connections within reach of the fluoride feed equipment should be provided with a hose bibb vacuum breaker.
6. Cross-connection control, in conformance with state regulations, must be provided.
7. State personnel should keep records on the amount of fluoride used at each school.

# B. Sodium Fluoride Saturator Systems
1. Manually filled saturators should be used in all school fluoridation systems. Upflow saturators generally are recommended because less maintenance is required. Make-up water (i.e., replacement water for the saturator) should be added manually for the following reasons: a. Greater protection from an overfeed will be provided because only a finite amount of solution is available and no continuously active (i.e., "hot") electrical outlet will be necessary; and b. Potential problems with sticking solenoid valves are eliminated.
2. The metering pump must be installed so that it cannot operate unless water is being produced (interlocked). For example, the metering pump must be wired electrically in series with the flow switch and the main well pump.
3. The metering pump must be plugged only into the circuit containing the overfeed protection; it must be physically impossible to plug the fluoride metering pump into any continuously active ("hot") electrical outlet. The pump should be plugged only into the circuit containing the interlock protection. One method of ensuring interlock protection is to provide on the metering pump a special, clearly labeled plug that is compatible only with a special outlet on the appropriate electrical circuit. Another method of providing interlock protection is to wire the metering pump directly into the electrical circuit that is tied electrically to the well pump or service pump, so that such hard wiring can be changed only by deliberate action. These methods are especially important with an upflow saturator installation because a solenoid valve requires the continuously active ("hot") electrical connection.
4. A flow switch, which is normally in the open position, must be installed in series with the metering pump and the well pump so that the switch must close to activate the metering pump. Flow switches should be properly sized and installed to operate in the flow range encountered at the school. It should be installed upstream from the fluoride injection point.
5. Metering pumps should be sized to feed fluoride near the midpoint of their range for greatest accuracy. Pumps should always operate between 30%-70% of capacity. Metering pumps that do not meet design specifications should not be installed in schools. Oversized metering pumps should not be used because serious overfeeds can occur if settings on the pump are too high. Conversely, undersized metering pumps can cause erratic fluoride levels.
6. The fluoride metering pump should be located on a shelf not more than 4 feet (1.2 m) higher than the lowest normal level of liquid in the saturator. Many manufacturers recommend that metering pump be located lower than the liquid level being pumped (i.e., flooded suction). However, a flooded suction line is not recommended in water fluoridation.
7. The priming switch on the metering pump should be spring-loaded to prevent the pump from being started erroneously with the switch in the priming position.
8. Two diaphragm-type, antisiphon devices must be installed in the fluoride feed line when a metering pump is used. The antisiphon device should have a diaphragm that is spring-loaded in the closed position. These devices should be located at the fluoride injection point and at the metering pump head on the discharge side. The antisiphon device on the head of the metering pump should be selected so that it will provide the necessary back pressure required by the manufacturer of the metering pump.
9. All antisiphon devices must be dismantled and visually inspected at least once a year. Repair or replacement schedules should follow the manufacturer's recommendations. All antisiphon devices should be vacuum tested semiannually. Operation of a fluoridation system without a functional antisiphon device can lead to a serious overfeed.
10. Sediment filters (20 mesh) should be installed in the water make-up line going to the sodium fluoride saturators, between the softener and the water meter.
11. A flow restrictor with a maximum flow of 2 gallons (7.6 L) per minute should be installed on all upflow saturators.
12. In an upflow saturator, either an atmospheric vacuum breaker must be installed or a backflow preventor must be provided in accordance with state or local requirements for cross-connection control. The vacuum breaker must be installed according to the manufacturer's recommendations.
13. A master meter on the school water service line and a make-up water meter on the saturator water line are required so that calculations can be made to confirm that the proper amounts of fluoride solution are being fed. These meters should be read daily and the results recorded.
A check valve should be installed in the main water line near the wellhead (in addition to any check valve included in the submersible pump installation). The check valve should be tested at least annually for leakage.
15. The water used for sodium fluoride saturators should be softened whenever the hardness exceeds 50 ppm (or even less if clearing stoppages or removing scale becomes labor intensive). Only the water used for solution preparation (i.e., the make-up water) needs to be softened. 16. Unsaturated (i.e., batch-mixed) sodium fluoride solution should not be used in water fluoridation.
17. Only granular sodium fluoride should be used in saturators because both powdered and very fine sodium fluoride can cause plugging in the saturator.
18. The minimum depth of sodium fluoride in a saturator should be 12 inches (30.5 cm). This depth should be externally marked on the saturator tank.
The saturator should never be filled so high that the undissolved chemical is drawn into the pump suction line.
19. All sodium fluoride chemicals must conform to the AWWA standard (B-701) to ensure that the drinking water will be safe and potable (43 ).

# C. Testing Equipment
1. The colorimetric method (SPADNS) of fluoride analysis is recommended for daily testing in school water fluoridation. If interferences are consistent (e.g., from iron, chloride, phosphate, sulfate, or color), the final fluoride test result can be adjusted for these interferences. State laboratory personnel and the state school technician should reconcile the interference and make the appropriate adjustment.
2. Distillation is not needed when the colorimetric method (SPADNS) of fluoride analysis is used for testing daily fluoride levels.

# IV. Safety Procedures
Fluoride remains a safe compound when maintained at the optimal level in the water supplied to a school water system; however, the school technician could be exposed to excessive levels if proper procedures are not followed or if equipment malfunctions. Thus, the use of PPE is required when fluoride compounds are handled or when maintenance is performed on fluoridation equipment. The state should develop a written program for schools regarding the use of PPE. 2. An eye wash solution should be readily available and easily accessible.

# Exposure to fluoride chemicals
If the operator gets dry chemicals on the skin, he or she should thoroughly wash the contaminated skin area immediately and should change work clothing daily no later than the close of the work day (51).

# B. Recommended Emergency Procedures for Fluoride Overfeeds

# Fluoride overfeeds
When a school system fluoridates its drinking water, a potential exists for a fluoride overfeed. Most overfeeds do not pose an immediate health risk; however, some can be high enough to cause immediate health problems. All overfeeds should be corrected immediately because some can cause long-term health effects (52)(53)(54)(55).
a. Specific actions should be taken when equipment malfunctions or an adverse event occurs that causes a fluoride chemical overfeed in a school public water supply system (Table 6).
b. When a fluoride test result is at or near the top end of the analyzer scale, the water sample must be diluted and retested to ensure that high fluoride levels are accurately measured.

# Ingested fluoride overdose
Persons who ingest dry fluoride chemicals should receive emergency treatment (Table 3) (10,(56)(57)(58)(59)(60)(61)(62). Naturally fluoridated water system: A public water system that produces water that has fluoride from naturally occurring sources at levels that provide maximum dental benefits.
Nontransient, noncommunity water system (NTNCWS): A public water system that is not a community water system and that regularly serves at least 25 of the same persons more than 6 months per year.
Optimal fluoride level: The recommended fluoride concentration (mg/L) based on the annual average of the maximum daily air temperature in the geographical area of the fluoridated water system.
Overfeed, fluoride: Any fluoride analytical result above the recommended control range of the water system. Different levels of response are expected from the operator depending on the extent of the overfeed (Tables 1 and 6).

# Public water system (PWS):
A system that provides piped water to the public for human consumption. To qualify as a public water system, a system must have 15 or more service connections or must regularly serve an average of at least 25 individuals 60 or more days per year.

# Recommended control range:
A range within which adjusted fluoridated water systems should operate to maintain optimal fluoride levels. This range is usually set by state regulation.

# School technician:
A state employee (usually from either the dental or drinking water program) whose primary responsibility is to provide for site visits, assist in the training of school fluoridation monitors, provide surveillance of all fluoridated school water systems, and resolve problems. This person functions as the water plant operator for a school fluoridation system and may be either an engineer or a technician.

# School water system:
A nontransient, noncommunity water system that serves only a school.

# Split sample:
A distribution water sample taken by the water plant operator, who analyzes a portion of the sample and records the results on the monthly operating report to the state. The operator then forwards the remainder of the sample to the state laboratory or to a state-approved laboratory for analysis.
State: This term includes the 50 contiguous states and U.S. territories.

# State fluoridation administrator:
A state employee (usually from either the dental or drinking water program) who is responsible for the administration of the fluoridation program.

# State fluoridation specialist:
A state employee (usually from either the dental or drinking water program) whose primary responsibility is to provide for site visits, assist in the training of water plant operators, provide surveillance of all fluoridated water

# Introduction
The purpose of this report is to provide data in summary form to describe the quality of fluoridation in each state as determined by the ability of fluoridating systems to conduct monitoring and maintain optimal fluoride levels.
General Instructions
All community water systems in the state that adjust the fluoride concentrations of their drinking water supply should be included in this report.
The optimal fluoride level for a particular system is to be based on the annual average of maximum daily air temperature for the geographic area over a 5-year period.
Instructions for Completing Form Item 1.
Record the state name.

# Item 2.
Enter the quarter covered by the report. The reporting period is the 3-month quarter beginning in January, April, July, or October. Reports are requested within 60 days after the end of reporting period.

# Item 3.
Provide an update on the following:
A. Record previous quarter's total systems and population.

# B.
The names of systems that began fluoridating during the quarter, date started, and the total population served.

# C.
The names of systems that discontinued fluoridating during the quarter, date discontinued, and the population that was served. NOTE: This does not include systems with temporary interruption of service. These fall into Item 4 or Item 5.

# D.
The total number of fluoridated systems at the end of the quarter and the total population served.

# Item 4.
Report the total number of systems and population served that did not report required sampling in any month of the reporting period as determined by either or both of the following criteria:
Exhibit A

# Introduction
The purpose of this report is to provide data in summary form to describe the quality of fluoridation in each state as determined by the ability of fluoridating schools to conduct monitoring and maintain optimal fluoride levels.
General Instructions
All school water systems in the state that adjust the fluoride concentrations of their drinking water supply should be included in this report.
The optimal fluoride level for a particular system is to be based on the annual average of maximum daily air temperature for the geographic area over a 5-year period. This optimal fluoride level is the community optimal level multiplied by 4.5 for use in schools.
Instructions for Completing Form Item 1.
Record the state name.

# Item 2.
Enter the quarter covered by the report. The reporting period is the 3-month quarter beginning in October, January, and April. Reports are requested within 60 days after the end of reporting period.

# Item 3.
Provide an update on the following:
A. Record previous quarter's total schools and population.

# B.
The names of schools that began fluoridating during the quarter, date started, and the total population served.

# C.
The names of schools that discontinued fluoridating during the quarter, date discontinued, and the population that was served. NOTE: This does not include schools with temporary interruption of service. These fall into Item 4 or Item 5.

# D.
The total number of fluoridated schools at the end of the quarter and the total population served.

# Item 4.
Report the total number of schools and population served that did not report required sampling in any month of the reporting period as determined by either or both of the following criteria:

# Glossary of Technical Terms
Adjusted fluoridated water system: A community public water system that adjusts the fluoride concentration in the drinking water to the optimal level for consumption (or within the recommended control range).

# Calculated dosage:
The calculated amount of fluoride (mg/L) that has been added to an adjusted fluoridated water system. The calculation is based on the total amount of fluoride (weight) that was added to the water system and the total amount of water (volume) that was produced.
Census designated place: A populated place, not within the limits of an incorporated place, that has been delimited for census purposes by the U.S. Bureau of the Census.

# Check sample:
A distribution water sample forwarded to either the state laboratory or to a state-approved laboratory for analysis.
Community: A geographical entity that includes all incorporated places as well as all census-designated places as defined by the U.S. Bureau of the Census.

# Community public water system (CWS):
A public water system that serves at least 15 service connections used by year-round residents or that regularly serves at least 25 year-round residents.
Consecutive water system: A public water system that buys water from another public water system. For purposes of water fluoridation record keeping, the consecutive water system should purchase at least 80% of its water from a fluoridated water system.

# Distribution sample:
A water sample taken from the distribution lines of the public water system that is representative of the water quality in the water system.
Fluoridated water system: A public water system that produces water that has fluoride from either naturally occurring sources at levels that provide maximum dental benefits, or by adjusting the fluoride level to optimal concentrations.

# Incorporated place:
A populated place possessing legally defined boundaries and legally constituted government functions.

# Monitoring, fluoride:
The regular analysis and recording by water system personnel of the fluoride ion content in the drinking water.

# Natural fluoride level:
The concentration of fluoride (mg/L) that is present in the water source from naturally occurring fluoride sources.
systems, and resolve problems. This person may be either an engineer or a technician.

# Surveillance, fluoride:
The regular review of monitored data and split sample or check sample results to ensure that fluoride levels are maintained by the community water systems in a specific geographic area. The review is conducted by a source independent of the water system.
Uniform flow: When the rate of flow of the water past a point varies by less than 20%.
Upstream: In a water line, a point closer to the source of water.
Water, make-up: Water that is used to replace the saturated solution from a sodium fluoride saturator; this saturated solution is pumped into the distribution lines.

# Water fluoridation:
The act of adjusting the fluoride concentration in the drinking water of a water system to the optimal level.
a.
Split/check Samples (check samples are acceptable if split samples are not available) should be included on the report if every quarterly or monthly split sample was not submitted.

# b.
Monitoring Reports -For systems required to monitor daily by the state, monitoring results were reported for less than 75 percent of days water was pumped; or for systems required to monitor less frequently, at least one monitoring result per week was not reported.

# Item 5.
Report the total number of systems and population served that failed to maintain optimal fluoride levels because of either of the following:
The mean of all fluoride verification samples, for each system, was more than 0.1 ppm below or 0.5 ppm above the optimal fluoride level for the system.

# b.
More than 25 percent of the monitoring samples, for each system, were more than 0.1 ppm below or 0.5 ppm above the optimal level (outliers). Report the number of systems and the population in this category.
NOTE: Systems that fail to maintain optimal levels should only be in Item 4 or Item 5--NOT BOTH.
Item 6. Report total number of systems and population served that have maintained optimal levels for all 3 months in the quarter. Do not include systems falling into Item 4 or Item 5 above.
Note: Items 4, 5, and 6 must equal End of Quarter total Item 3D.

# Item 7.
Report total number of systems and population served that had more than one-third of the split/check samples taken in the quarter deviating by more than plus or minus 0.2 ppm from the corresponding monitoring results.
Note: Systems included in this item may also be included in Items 4, 5, and 6.

# Revised 1985
Exhibit A -Continued  -----------------------------------------------------------------3.
END OF QUARTER STATISTICS:  -----------------------------------------------------------------4 -----------------------------------------------------------------5 -----------------------------------------------------------------6 -----------------------------------------------------------------7. ---------------------------------------------------------------- Verification Sample -a school should be included on the report if every weekly verification sample was not submitted.

# SYSTEMS WITH INADEQUATE CORRELATION BETWEEN CHECK SAMPLES AND MONITORING RESULTS

# Number of Systems: __________ Population Served: ___________

# b.
Monitoring Reports -For systems required to monitor daily by the state, monitoring results were reported for less than 75 percent of days water was pumped; or for systems required to monitor less frequently, at least one monitoring result per week was not reported.

# Item 5.
Report the total number of systems and population served that failed to maintain optimal fluoride levels because of either of the following:
a.
The mean of all fluoride verification samples, for each school, was more than 0.5 ppm below or 1.5 ppm above the optimal fluoride level for the system.
b.
More than 25 percent of the monitoring samples, for each school, were more than 0.5 ppm below or 1.5 ppm above the optimal level (outliers).
Report the number of systems and the population in this category.
NOTE: Schools that fail to maintain optimal levels should only be in Item 4 or Item 5--NOT BOTH.
Item 6. Report total number of schools and population served that have maintained optimal levels for all 3 months in the quarter.  -----------------------------------------------------------------3.
END OF QUARTER STATISTICS:  -----------------------------------------------------------------4 -----------------------------------------------------------------5. -----------------------------------------------------------------6. ---------------------------------------------------------------- The Morbidity and Mortality Weekly Report (MMWR) Series is prepared by the Centers for Disease Control and Prevention (CDC) and is available free of charge in electronic format and on a paid subscription basis for paper copy. To receive an electronic copy on Friday of each week, send an e-mail message to lists@list.cdc.gov. The body content should read subscribe mmwr-toc. Electronic copy also is available from CDC's World-Wide Web server at / or from CDC's file transfer protocol server at ftp.cdc.gov. To subscribe for paper copy, contact Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402; telephone (202) 783-3238.

# SUMMARY OF SCHOOLS NOT MEETING OPTIMAL LEVELS

# Number of Schools: __________ Population Served: ___________

# SUMMARY OF SCHOOLS MEETING OPTIMAL LEVELS

# Number of Schools: __________ Population Served: ___________
Data in the weekly MMWR are provisional, based on weekly reports to CDC by state health departments. The reporting week concludes at close of business on Friday; compiled data on a national basis are officially released to the public on the following Friday. Address inquiries about the MMWR Series, including material to be considered for publication, to: Editor, MMWR Series, Mailstop C-08, CDC, 1600 Clifton Rd., N.E., Atlanta, GA 30333; telephone (404) 332-4555.
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# 6U.S. Government Printing Office: 1995-633-175/27014 Region IV