The Ohio Department of Health (ODH) offers public health guidance for specific types of facilities or businesses after a public water system issues a drinking water advisory for cyanotoxins. 

Types of Advisories

Ohio communities and/or public water systems issue two types of drinking water advisories depending upon the level of HAB toxins.

Note that values are reported in μg/L (microgram per cubic liter), which is equal to one (1) part per billion (ppb). 

Precautions During a Drinking Water Advisory

During a drinking water advisory for children under six and sensitive populations, an alternative water source, such as bottled water, should be used for drinking, preparing food, making infant formula, brushing teeth, and making ice for these individuals. 

• Children six years and younger should be supervised when bathing to prevent accidental ingestion. 

• Skin irritation, such as a rash may occur from exposure when washing hands and bathing. 

• Providing a final rinse of skin with uncontaminated water is recommended, especially for items that go into the mouths of infants and children under the age of six years (i.e., teething rings, nipples, bottles, toys, silverware). 

During a drinking water advisory for children and adults, alternative water should be used for drinking (including pets), making infant formula, making ice, brushing teeth and preparing food. 

• The cautions listed for children under six and sensitive populations listed above still apply. 

• During a drinking water advisory, healthy individuals may continue to use the water for washing hands, bathing, washing dishes, and doing laundry. 

For all advisories: 

• Do not boil the water. Boiling the water will not remove the toxins. 

• You may use water for flushing toilets. 

Public Health Guidance for Specific Settings During Drinking Water Advisories

ODH offers guidance for specific settings after a community and/or a public water system issues a drinking water advisory. Expand the sections below for more information about what guidance ODH offers for each setting. 

Ambulatory Surgical Facilities

At both advisory levels ambulatory surgical facilities should not use tap water for patient care that includes washing open wounds or exposed tissues unless the water has been treated at the facility to remove toxins.  Ambulatory surgical facilities that pre-treat water from the local public water supply using reverse osmosis(for removal of all toxins), nanofiltration (for removal of all toxins except anatoxin-a), or for microcystin advisories, use of continuous disinfection with chlorine as per recommended treatment specifications may continue to use the water for patient care.  

Regular testing of the treated water for cyanotoxins is required to ensure toxin removal.   Ambulatory surgical facilities without appropriate water treatment should reschedule elective surgeries when possible. 

Birthing Centers

At both advisory levels, birthing centers should not use tap water for patient care that includes washing open wounds or exposed tissues unless the water has been treated at the facility to remove toxins.  Birthing centers that pre-treat water from the local public water supply using reverse osmosis (for removal of all toxins), nanofiltration (for removal of all toxins except anatoxin-a), or for microcystin advisories, use of continuous disinfection with chlorine as per recommended treatment specifications may continue to use the water for patient care.   Regular testing of the treated water for cyanotoxins is required to ensure toxin removal.  

Campgrounds/Resident Camps

Campgrounds and residential camps should follow the drinking water advisory issued by the local community and/or public water system. 

Tap water may be safely used for cleaning surfaces in facilities.

Also follow any public health advisory for recreational waters if issued by the Ohio Department of Health.

Click here for HABs information for campground operators and owners of private ponds and lakes.

Daycare/Day Camp/Preschool Facilities

Daycare, day camp and preschool facilities should follow the drinking water advisory issued by the local community and/or public water system. 

As a precaution, surfaces that children may put their mouths on, such as toys and teethers, should be rinsed with an alternative water source such as bottled water. Tap water may be safely used for cleaning surfaces that children will not put their mouths on.

Dental Offices/Clinics

At both advisory levels, dental offices and clinics should not administer water to patients through the dental unit, ultrasonic scaler, or other dental equipment that uses the local public water system. This restriction does not apply if the water source is isolated from the local public water system (e.g., a separate water reservoir or other water treatment device approved to remove algal toxins).

Patients should rinse with bottled or distilled water until the drinking water advisory has been cancelled. 

During these advisory periods, tap water should not be used to dilute germicides or for hand hygiene.  For hand hygiene, antimicrobial products that do not require water (e.g., alcohol-based hand rubs) can be used.  If hands are visibly contaminated, bottled water and soap should be used for hand washing; if bottled water is not immediately available, an antiseptic towelette should be used.

Tap water may be safely used for cleaning surfaces in the dental office/clinic. 

Dialysis Centers

At both advisory levels, dialysis centers should not use tap water in dialysis units. Dialysis units that pre-treat water from the public water supply to ANSI/AAMI 26722, ANSI/AAMI 13959, ANSII/AAMI 11663 and ANSI/AAMI 23500  standards using reverse osmosis (for removal of all toxins) or nanofiltration (for removal of all toxins except anatoxin-a) or for microcystin advisories, use of continuous disinfection with chlorine (specify types and CT values) may continue to use the water for dialysis. 

Dialysis centers may consider using pre-packaged dialysate throughout the duration of a drinking water advisory.   All dialysate water, except for pre-packaged dialysate, must be frequently tested after treatment to ensure the efficacy of the treatment unit prior to use.

In-Home Dialysis

At both advisory levels, in -home dialysis units should not use tap water in dialysis units. Dialysis units that pre-treat water from the public water supply to ANSI/AAMI 26722. ANSI/AAMI 13959, ANSII/AAMI 11663 and ANSI/AAMI 23500  standards using reverse osmosis (for removal of all toxins) or nanofiltration (for removal of all toxins except anatoxin-a) or for microcystin advisories, use of continuous disinfection with chlorine (specify types and CT values) may continue to use the water for dialysis. In-home dialysis users may consider using pre-packaged dialysate throughout the duration of a drinking water advisory. All dialysate water, except for pre-packaged dialysate, must be frequently tested after treatment to ensure the efficacy of the treatment unit prior to use.

Fire Departments

During a drinking water advisory issued by a public water system, exposure to aerosolized cyanotoxins may occur during spraying of water for fire suppression.  Firefighters should consider wearing personal protective equipment to prevent the inhalation of aerosolized water during fire suppression activities.  

Water used for fire suppression from surface water sources containing an active algal bloom are at increased exposure risk and should wear personal protective equipment to prevent the inhalation of aerosolized water during fire suppression activities.

Food and Beverage Manufacturing

• Ice – Follow the drinking water advisory issued by the local community and/or public water system. Check their website or ohioalgaeinfo.com for information.

• Bottling/Canning – Follow the drinking water advisory issued by the local community and/or public water system.

• Microbreweries – Follow the drinking water advisory issued by the local community and/or public water system. 

Food Service Operations

• Ice Machines and Bulk Water Machines – Follow the drinking water advisory issued by the local community and/or public water system. 

• Dishwashing/Equipment – Food service operations may wash dishes with tap water when a final chlorine rinse is used that meets Ohio Food Code specifications for manual and mechanical ware washing equipment for microcystin advisories.  If chlorine sanitizer is not used, cleaned dishes may be rinsed with an alternative water source (e.g., bottled water) to remove any residue that might contain minute levels of cyanotoxins.  Use of a post sanitizing rinse with tap water is not recommended.

• Cleaning Surfaces – Tap water may be safely used for cleaning surfaces that will not come into contact with food.

Retail Food Establishments

At both drinking water advisory levels, retail food establishments should not mist produce with tap water; use an alternate water source instead.  Also rinse vegetables with an alternative water source.  Do not use tap water for filling or topping off fish/crustacean tanks.  Tap water may be safely used for cleaning surfaces that will not come into contact with food.

Home Health

At both drinking water advisory levels, tap water should not be used for washing or cleaning exposed tissue or wounds in the home health setting. Follow the drinking water advisory issued by the local community and/or public water system. 

Click here for information on what residents should do after a HABs advisory has been lifted.

Hospice

At both drinking water advisory levels, tap water should not be used for washing or cleaning exposed tissue or wounds in the hospice setting. Follow the drinking water advisory issued by the local community and/or public water system. 

Hospitals

At both drinking water advisory levels, hospitals should not use tap water for patient care that includes washing open wounds or exposed tissues unless the water has been treated at the facility to remove toxins.  Hospitals that pre-treat water from the local public water supply using reverse osmosis(for removal of all toxins), nanofiltration (for removal of all toxins except for anatoxin-a) or for microcystin advisories, use of continuous disinfection with chlorine as per recommended treatment specifications may continue to use the water for patient care.  

Regular testing of the treated water for cyanotoxins is required to ensure toxin removal.   Hospitals without appropriate water treatment should reschedule elective surgeries when possible.

• Sterilization – Clean steam autoclaves with reverse osmosis treatment are acceptable for use.  Steam autoclaves should not use tap water for generating steam.

• Washing Surfaces – Continue to follow CDC Guidelines for Sterilizing and Disinfecting Patient-Care Items and Environmental Surfaces. Do not dilute disinfectants with contaminated tap water. 

• Washing Linens/Bedding – Continue to follow CDC Guidelines for Sterilizing and Disinfecting Patient-Care Items and Environmental Surfaces.  Do not dilute disinfectants with contaminated tap water.

• Wound Care – Tap water should not be used for washing or cleaning exposed tissue or wounds.

• Skin Conditions (e.g., eczema) – Skin irritation, such as a rash, may occur from exposure when bathing and washing hands.  Providing a final rinse of skin with uncontaminated water is recommended.

Nuclear Power Stations

At both drinking water advisory levels, nuclear power plants may safely continue to use water per normal procedures. Cyanotoxins do not evaporate from water, so there is no risk from steam.

Office Buildings

Office building should follow the drinking water advisory issued by the local community and/or public water system. 

Tap water may be safely used for cleaning surfaces in the building.

Pet Stores

At both drinking water advisory levels, pet stores should not use tap water as drinking water for animals.  Do not bathe animals using tap water as they will lick and groom themselves after bathing.  Do not use tap water for filling or topping off fish/crustacean/amphibian tanks.

Pools/Water Parks/Spas

At both drinking water advisory levels for microcystin advisories, swimming pools, water park and spa features that use tap water should super-chlorinate the facility using standard procedures.  For other cyantoxins in the water source for the facility, please consult the Ohio Department of Health Recreation Program.

Follow any public health advisory for recreational waters if issued by the Ohio Department of Health.

Private Homes

• Hand Washing – Guidance depends upon the drinking water advisory level.  Follow the advisory issued by the local community and/or public water system. 

• Brushing Teeth – Guidance depends upon the drinking water advisory level.  Follow the advisory issued by the local community and/or public water system.

• Showering/Bathing – Guidance depends upon the drinking water advisory level.  Follow the advisory issued by the local community and/or public water system.

• Cooking – Guidance depends upon the drinking water advisory level.  Follow the advisory issued by the local community and/or public water system.

• Dishwashing – Dishes may be washed with tap water.  After washing, dishes may be rinsed with an alternative water source such as bottled water to remove any residue that might contain minute levels of cyanotoxins. 

• Cleaning Surfaces – As a precaution, surfaces that children may put their mouths on, such as toys and teethers, should be rinsed with an alternative water source such as bottled water.

• Laundering Clothes – Clothing may be laundered safely with tap water. 

• In-Home Nebulizer/CPAP/BiPAP – In-home nebulizers or CPAP/BiPAP components should not be washed with tap water; use an alternative water source instead such as bottled water.

• Lawn and Recreational Water Exposure – Closely observe and monitor children playing in lawn recreation devices such as sprinklers to prevent ingestion of the contaminated water.

• Point-of-Use or Whole House Water Treatment Devices – Limited testing of point-of-use or whole house water treatment devices such as pitchers with filters and countertop or under-sink mounted treatment units has been conducted by  independent testing agencies such as NSF International, Water Quality Association or the Underwriters Laboratory (UL) for their ability to remove cyanotoxins from drinking water. .  Consumers should carefully review any product removal claims to ensure the product has been tested by a reputable third-party testing agency prior to use.   Research suggests that reverse osmosis can remove all toxins or nanofiltration systems for removal of all toxins except for anatoxin-a, from drinking water but independent testing and approval of specific systems for residential use is not available.  

• Personal Water Containers – Containers individuals bring from home to transport water from a water distribution facility during a drinking water advisory should be marked or rated as safe for contact with drinkable water.  Containers used to store food or beverages are considered safe for contact with drinkable water.  Milk jugs or juice bottles may be used to transport water if they are thoroughly washed, rinsed and sanitized.  Utility buckets and similar containers are not considered safe for contact with drinkable water and may release other undesirable chemicals into the stored water.  Please remember that water weighs 9.3 pounds per gallon; be sure to determine how much water can be carried or transported safely in a container.

• Flushing of Residential Water Lines – Homeowners should follow the recommendations for flushing water lines and replacement of water filter devices for appliances or point-of-use treatment systems after a drinking water advisory is lifted. 

Private Water Systems

During a drinking water advisory, follow private water system recommendations for the treatment of ponds or groundwater systems, such as spring and water well systems.

Residential Care/Assisted Living Facilities

Residential care and assisted living facilities should follow the drinking water advisory issued by the local community and/or public water system. Check their website or ohioalgaeinfo.com for information.

Skilled Nursing/Long-Term Care Facilities

At both drinking water advisory levels, skilled nursing facilities should not use tap water for patient care that includes washing open wounds or exposed tissues unless the water has been treated at the facility to remove toxins. 

Facilities that pre-treat water from the local public water supply using reverse osmosis, nanofiltration or continuous disinfection with chlorine as per recommended treatment specifications may continue to use the water for patient care.  

Facilities should follow the drinking water advisory issued by the local community and/or public water system. 

Schools and Universities

Schools and universities should follow the drinking water advisory issued by the local community and/or public water system. 

Also follow any public health advisory for recreational waters if issued by the Ohio Department of Health.  Tap water may be safely used for cleaning surfaces in facilities.

Women, Infant and Children (WIC) Program Recipients

WIC participants should follow the drinking water advisory issued by the local community and/or public water system. 

WIC participants may go to their local WIC Clinic on the next business day to have any remaining formula benefits for the current month changed to ready-to-feed formula.  Formula changes will be for the current month only.  Should the drinking water advisory continue into a new month, formula benefit changes must be pursued again.

Please contact the Bureau of Environmental Health and Radiation Protection at BEH@odh.ohio.gov or at (614) 466-1390  for questions or additional information.