ON
THE WAKE OF THE SANTA PAULA EXPLOSION, MANY WASTEWATER TREATMENT PLANTS DO NOT
COMPLY WITH THE 2012 NFPA STANDARD 820
There have been infrequent fire or explosion incidents at wastewater
treatment plants; infrequent but sever,
just like the one at the Santa Paula plant.
The purpose of the NFPA 820 standard is to provide a degree of fire and explosion
protection and reduce or eliminate the effects of fire or explosion at
wastewater collection, transportation, and treatment facilities.
Another purpose is to reduce or eliminate the effects of fire
or explosion by maintaining structural integrity, controlling flame spread and
smoke generation, preventing the release of toxic products of combustion, and
maintaining serviceability and operation of the facility.
NFPA 820 establishes minimum requirements for protection. The standard applies to new installations and
to additions or modifications to existing facilities. It should be used by designers/owners in risk
assessment for existing facilities.
Hazardous Area Definitions
▪ Class I, Div 1: Where ignitable
concentrations of flammable vapors are present under normal operation
conditions
▪ Class I, Div 2: Where ignitable
concentrations of flammable vapors are present under abnormal operating
conditions
▪ Class II, Div 1: Where ignitable
concentrations of combustible dusts are present under normal operating
conditions
▪ Class II, Div 2: Where ignitable
concentrations of combustible dusts are present under abnormal operating
conditions
The problem is that NFPA 820 has not been widely adopted due to
the costs associated in complying with its requirements. Furthermore, plants built prior to 1990
typically have areas that do not comply with NFPA 820. Issues at existing plants include: no physical separation between a classified
location and unclassified location; gas tight partition required between
classified location and unclassified location.
Areas at existing plants that should be classified as Class I, Div 2 are
not classified at all, creating fire and explosion hazards. Storage areas for hazardous chemicals used in
the treatment of the wastewater (such hydrogen peroxide, acids, bases, etc.)
need to properly classified and separated from other areas.
Chemical and other
Health Risks to Workers at Wastewater Treatment Plants
Working in the field of wastewater treatment can be a hazardous
profession. We recently requested
information from the National
Institute for Occupational Safety and Health (NIOSH) in regards to health
& safety for wastewater workers. In
short, NIOSH stated that there has not been a lot of research on the health of
wastewater workers and that NIOSH continues to study this issue.
The following are some suggestions that may help workers in
this field to stay healthy on the job. These are only suggestions and they are
not intended to be policy and are not all inclusive. Depending on your
circumstances and location, you may be subject to laws, rules or regulations in
regards to health and safety for wastewater workers. It is the responsibility
of the facilities and workers to review their own situations and apply the
appropriate safeguards to assure a safe working environment. Additional
safeguards and consideration beyond those discussed in this document and
related attachments may apply to your facility. Review and updating of safety
policies needs to occur on a continuing basis.
Water borne disease is a concern for wastewater workers.
Currently (as of July 1, 1998) The
National Institute for Occupational Safety and Health (NIOSH) has made no
official recommendations regarding vaccinations for workers who contact sewage.
NIOSH does point out that sewage workers, like all adults, should be current on
their tetnus-diphtheria immunization. NIOSH also pointed out that there is
continuing study on hepatitis A vaccinations for sewage workers. NIOSH (along
with several other agencies and researchers) do acknowledge that there may be
some potential risk for water borne pathogens and they further state that one
of the best defenses against water borne disease for sewage workers is to
practice good hygiene and good house keeping.
Workers at wastewater facilities should wash their hands
frequently with anti-bacterial soap. Be sure to wash thoroughly and scrub under
nails with a brush. Especially be sure to wash up before eating, smoking or
drinking.
Open cuts or wounds should be protected, be sure to replace
contaminated dressings.
Avoid direct contact with wastewater, always wear rubber gloves
and protective clothing when working with wastewater.
Do not wear contaminated or soiled clothing, wash work clothes
regularly to remove contaminants. It is suggested that work clothing for
wastewater workers be washed on-site, it IS NOT recommended to bring
sewage contaminated clothing home. Let your work clothing (and work boots)
remain at work. Bringing the contaminated clothing home may expose other family
members to pathogens. It is also recommended that you take a shower at the end
of your shift.
In spite of our best efforts, at times thing may go wrong that
result in copious amounts of wastewater or wastewater residues spewing forth
onto workers. If you get sprayed or soaked down with sewage or sewage residues,
change clothes and take a shower.
Keep your fingernails short and DO NOT bite your nails!
DO NOT stick your fingers or hands in your mouth, nose, eyes or
ears.
One of the biggest dangers faced by workers in wastewater
systems is ‘Confined
Spaces". There are many dangers associated with confined spaces with
one of the primary hazards being atmospheric. The potential for deadly
environments exists in confined space areas. Workers need to be able to
identify and deal with hazards associated with confined spaces. Examples of
confined spaces in wastewater system include (but are not limited to), manholes,
sewers, pipelines, storage tanks, wetwells, digesters and pump stations.
Additionally, atmospheric hazards may exist in other areas where wastewater or
wastewater residues are processed. The use of personal gas detection equipment
while working in a wastewater facility is recommended. It is recommended that
wastewater workers obtain and follow all OSHA requirements
for working in confined spaces.
As mentioned above, atmospheric hazards may exist anywhere in a
wastewater treatment system where wastewater or wastewater residues (biosolids)
are processed. As a result of the natural decomposition and treatment of
wastewater or wastewater residues, gases are produced and or consumed. Examples
of the gases produced include methane, hydrogen sulfide, and carbon dioxide.
Additionally, oxygen may be displaced or consumed by organisms thus resulting
in a oxygen depleted atmosphere. Atmospheric hazards can also come from
industrial or commercial sources as well. There are documented cases of
gasoline finding its way into sewer systems. The use of fixed or permanent
mounted gas detection equipment (in addition to personal gas detection) will
protect property and lives. Be sure to calibrate and maintain gas detection
equipment as per manufacturers recommendations. Atmospheric and explosion hazards
are especially prevalent at facilities that utilize anaerobic digestion in
their treatment process. There are several documented cases of treatment
facilities exploding and workers being killed as a result of methane explosions
at treatment facilities using anaerobic digestion.
Drowning is also a serious threat at wastewater facilities.
There are several documented cases of workers and officials drowning in
wastewater systems. Extreme currents and process equipment make the wastewater
system a deadly environment from the standpoint of drowning. Be sure that there
is railing around all process tankage and pits. If you must work inside the
railing area, be sure to wear a life line and personal flotation device (PFD).
Rescue buoys and throw bags are also a good idea. Be sure to locate rescue
equipment in easy to access areas in wastewater systems. Remember, the use of
PFD’s is always a good idea when working near waterways.
Traffic hazards can pose threats to workers and motorists
alike. Be sure to properly set up traffic zones and controls when working on
streets. Additional regulatory requirements may apply especially if digging up
a state owned highway.
Collapse of trenches can cause serious injury or death, be sure
to utilize proper techniques for trenching and shoring when you are digging.
Call before you dig (PA One Call System). Digging up or
rupturing lines such as power lines or gas lines can be hazardous or deadly!
Locate all underground utilities before you start to dig. The Pennsylvania One
Call System 1-800-242-1776, CALL BEFORE YOU DIG! The PA One Call System
notifies all utilities of any excavation work to be performed enabling them to
locate and mark their utility lines. PA Act 38 of 1991 requires notification to
a one call system three (3) working days prior to the start of any digging.
Chemical hazards are also present at wastewater treatment
facilities. In some cases (such as chlorine), the chemical hazard may be
deadly. Be sure to read and understand the MSDS for the chemical product you
are working with. The MSDS for all products should be easily accessible to both
system workers and emergency responders. Be sure to follow all recommendations
for personal protective equipment when working with chemical products. Clean up
all chemical spills promptly. Depending on the type and quantity of chemical
spilled, you may also need to report the spill to your county Emergency
Operations Center. Refer to your states emerging response system for more
information on reporting requirements for chemicals you have on site. For
example, if you have 100 pounds or more of chlorine on site, planning and
reporting requirements are triggered. Chemical hazards may also be present at the
industries connected to your system. Sewer use ordinances should include
provisions to prohibit dangerous substances from entering the sewer systems,
spill prevention and containment plans can prevent disasters of this sort from
happening. Also, be sure you are familiar with the proper use and maintenance
of personal protective equipment and clothing. Using and maintaining equipment
such as Self Contained Breathing Apparatus (SCBA) requires training and
practice. Using this equipment in a hazardous environment needs to be second
nature, a mistake or panic in a dangerous environment could be disastrous!
Falls in wastewater system are a danger as well, the use of
fall protection devices can prevent serious injury. Good house keeping can help
by removing slipping or tripping hazards.
Fire and explosion in wastewater systems is a concern as well.
For more information on this subject it is recommended that wastewater systems
obtain a copy of "NFPA 820 Standard for Fire Protection in Wastewater
Treatment and Collection Facilities" The
National Fire Protection Association (NFPA) is located in Quincy, MA. The
NFPA 820 standard can be ordered directly from NFPA. You can find them on the
Internet.
There have been many documented injuries from heavy lifting in
wastewater treatment facilities. Most equipment found in wastewater systems is
quite heavy. Proper technique for lifting objects is necessary to prevent
injury. Crush injuries from this equipment is a threat as well.
Develop and integrate a safety program into your work
environment. A facility safety officer or safety committee can help to focus on
safety and health related issues. While prevention is always the best answer,
accidents continue to happen. It is a good idea to follow up after an accident
or injury to look at the cause so future accidents can be prevented. Be sure to
keep up with the latest regulations or standards as well as changes in safety
science that relate to your facility.
Regular medical surveillance (regular physical examination) is
a good idea and may even be a necessity especially for workers who are exposed
to hazardous materials.
Electrocution or mechanical hazards due to energizing circuits
on equipment being repaired or serviced is also a concern. Establish a
"Lock Out/Tag Out" procedure when working on process equipment to
prevent accidental starting of equipment. Physically locking out the breaker
and motor starter prevents these types of accidents. Similarly, valves to process
tanks should also be locked to prevent accidental flooding during maintenance.
The wastewater laboratory can present hazards to wastewater
workers. Often times, wastewater labs acids or poisonous reagents that must be
handled and stored properly. Examples of equipment you may want to have in your
lab include, acid storage cabinets, emergency deluge showers, eye wash
stations, appropriate fire extinguishers, fire blanket, fume hoods and spill
clean up kits. Always wear safety goggles, lab smock and gloves when working in
the lab. Eating, smoking or drinking in the lab IS NOT a good idea. Never
pipette by mouth as many reagents are corrosive and/or poisonous. DO NOT store
food in the same refrigerator with reagents or samples. Clean up all spills
promptly using the appropriate materials. All reagents and products in a lab
should be clearly labeled.
All facilities should develop plans on how to deal with
emergencies. Proper preplanning can save lives and property. Examples of
emergency plan topics could include subjects such as fire, explosion, flood,
spills into the sewer system, chemical releases, severe weather, medical
emergencies, or other natural and manmade disasters. It is a good idea to
occasionally test and update plans, especially where plans involve the interaction
of several agencies or groups. Voluntary employee emergency information sheets
can provide emergency medical workers with valuable information about the
injured person (especially if they are unconscious). Medical information is a
private matter and needs to be kept confidential. Coordinate where you would
keep employee information sheets and the needed information with emergency
medical personnel. Chaos, confusion and panic are some of the elements that may
accompany an emergency, proper planning can reduce or eliminate tragic
circumstances. Emergency planning needs to happen before the emergency occurs!
Anticipate and expect the UN-expected.
A proper emergency response program can provide help with
emergency planning and training people (hands-on) on the proper use of safety
equipment.
CHEMICAL EXPLOSION IN CALIFORNIA.
DOZENS WENT TO THE HOSPITAL.
A mysterious chemical mixture burst
into flames at a Ventura County waste facility on Tuesday, sending dozens to
hospitals for decontamination and emptying homes and businesses for a mile
around the plant before the danger eased, authorities said.
A vacuum truck exploded into flames
about 3:45 a.m. at the Santa Paula Waste Water Co., spreading about 1,200
gallons of a mysterious waste chemical mixture that contained sulfuric acid and
a highly combustible organic peroxide, fire officials said.
"As the liquid began to dry out,
the (fire engine) companies on scene noticed that it was very unstable and
reactive," Ventura County fire Capt. Mike Lindbery said. "As they
stepped on it or tried to move their engine, it would spontaneously ignite
under the tire of the engine or their boots."
No burn injuries were reported, but two
drivers on a vacuum truck, three firefighters, hospital medical staff and a few
nearby residents were washed down or treated for complaints such as breathing
problems, red eyes and skin rashes, said Lori Ross, a spokeswoman for the
Ventura County Fire Department.
SANTA
PAULA (CBSLA.com) — A chemical spill sparked multiple
explosions, sickening dozens and forcing nearby residents to evacuate their
Ventura County homes on Tuesday.
By late afternoon, investigators were preparing to move in as the
toxic smoke had diminished at the Santa Clara Water Waste Co.
Firefighters arrived at the scene about 3:45 a.m.
after reports that a vacuum truck had exploded. The truck was sitting in
the middle of the facility surrounded by a white substance that was spread by
the explosion. When firefighters looked down at their shoes, they saw the
material sparking into flames around their feet, and quickly got away ahead of
a series of explosions.
Ventura County fire Capt. Mike Lindberry told CBS2′s Randy
Paige that the material on the ground was a form of organic peroxide, a highly
volatile chemical that burns quickly. He said a big concern was nearby toxic
chemicals, including sulfuric acid and other corrosives, that would
create extremely hazardous smoke if they caught fire.
“We had acids burning, we had wood, we had everything in
the area, rubber on tires and boots burning,” Lindberry said. “The big
concern was the fact that if we were to have a large explosion we don’t
want people in that area.”
That meant mandatory evacuations for everyone within a mile of
the plant, and shelter-in-place orders for everyone within a 3-mile radius, as
well as the closure of Highway 126.
Lindberry said putting water on the fire could have caused even
bigger problems, including the potential contamination of the nearby Santa
Clara River. So firefighters had to wait for it to burn itself out.
At least 37 people were treated for exposure to the volatile
chemicals, with most complaining about irritated eyes and throats. All of the
injured, except the truck driver, were released.
Metropolitan
Engineering, Consulting & Forensics (MECF)
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