Plant Chemicals

Where gases are present, fires and explosions can occur. Chemical burns can occur from contact with chemicals used in the treatment process. Chemical feed and storage areas contain acids and alkalies. In the liquid form, these chemicals can cause burns to the eyes or skin. If the liquid is allowed to remain on clothing, it can soak through and cause burns. The dry form (powder, crystal, or pebble) of these chemicals is also hazardous and may cause burns when in contact with moist areas of the skin. Inhaling dry chemical dust or chemical fumes can result in burns to the nose, throat, and lungs. Polymers are very slippery and can present particularly hazardous working conditions. The work area, including floors, steps, and handrails, must be periodically washed down to avoid accidental falls, slips, and slides due to the presence of polymers.

A number of chemicals are used at the Glasgow WTP. The chemicals have been described individually in previous chapters. Additional information for some of the more hazardous chemicals is presented below.

Alum

Alum can be used at the WTP and stored in two, 275-gallon plastic totes in the alum storage room. The concentration of the alum used at the WTP is 48%. In general, alum is a colorless liquid that can irritate the skin and eyes, and is also corrosive. Alum is delivered to the WTP in totes or drums from the chemical supplier and safety precautions and proper procedures should always be followed. First aid measures include the following:

  • Eye Contact: Flush immediately with water for 15 minutes. If irritation persists, seek medical attention.
  • Skin Contact: Flush immediately with water for 15 minutes while removing contaminated clothing. If irritation persists, seek medical attention.
  • Inhalation: Remove from exposed area to fresh air. If irritation persists, seek medical attention.
  • Ingestion: Get medical attention immediately. If conscious, immediately give person water or milk (not more than 8 oz.) Induce vomiting. DO NOT give bicarbonate.

Accidental release measures are as follows:

  • Small spills: Wash down with large volumes of water. Spills can be neutralized with soda ash or lime, but neutralization will release CO2.
  • Large spills: Dike for later disposal. Pump residue into storage containers for later disposal. Neutralize with lime or soda ash. Neutralization will release CO2, which can generate a breathing hazard.

Handling and storage procedures are as follows:

  • Handling – Avoid contact with skin, eyes or clothing. Avoid breathing mist.
  • Storage – Store in closed containers in a cool, dry, well ventilated area away from sources of heat. Protect containers from physical damage. Liquid alum is corrosive to ferrous metals and mild steel. Use acid resistant tanks for storage and piping (plastic rubber lined, plastic lined, or stainless steel).
  • Engineering Controls – General ventilation must be provided. If misting conditions exist, local exhaust ventilation may also be needed. Eye wash stations and washing facilities should be readily accessible.
  • Personal Protective Equipment – Eye Protection: The use of chemical safety goggles and a face shield is recommended where splashing of material is possible. Do not wear contact lenses. Skin Protection: Avoid skin contact by wearing rubber or plastic gloves. Respiratory Protection: If misting conditions exist, wear an activated NIOSH approved mist respirator.

Chlorine

Chlorine gas is about 2 ½ times heavier than air, and consequently tends to collect in low areas. It is primarily a respiratory irritant which has a readily detectable odor at concentrations above 0.3 ppm. Exposure to concentrations of 1,000 ppm can be fatal in a relatively short time. Liquid chlorine will cause skin and eye burns. The plant personnel should become familiar with the properties of chlorine, the potential hazards associated with its use, the precautions to be observed, and the steps for emergency conditions. Detailed information is found in the U published by the Chlorine Institute, Inc., 50 East 51st Street, New York City, and in the Chlorine Safety Manual for Water and Wastewater Treatment Facilities published by the Water Environment Federation and developed by the New York State Emergency Response Commission, Chlorine Advisory Board, 1994.

Chlorine is delivered to the plant in 150-pound cylinders, which should never be dropped or allowed to hit one another. Containers that have been in storage longest should always be used first.

Leaks around valve stems can normally be eliminated by tightening the valve stem packing. If a leak occurs in a pipe, the defective piping should be replaced after the residual chlorine has been exhausted. Do not repair by welding – steel burns in the presence of chlorine at elevated temperatures. If a leak is found on a chlorine container, it should be rotated so that chlorine gas rather than liquid chlorine escapes.

Two people should always be present when unloading, connecting, or disconnecting chlorine containers. The operator should wear a self-contained breathing apparatus when performing these duties while another person acts as a safety observer.

Listed below are a few recommended safety rules when dealing with chlorine:

  • Keep protective caps on containers which are not in use.
  • Regularly test for chlorine leaks at each valve or connection.
  • Do not store self-contained breathing apparatuses in the same room as the chlorine equipment.
  • Open container valves slowly and never use wrenches over 6 inches long.
  • Prevent moisture from entering the chlorination system.
  • Always keep ventilation system in operation.
  • Protect chlorine tanks from direct heat.
  • Avoid manifolding containers together that have uneven pressure or temperature.
  • In case an individual has been exposed to chlorine, the following actions are recommended:
  • Remove person from gas area immediately.
  • If a significant quantity of chlorine is in the person’s eyes or clothes, wash those areas at the exterior deluge showers.
  • Keep individual as quiet and as warm as possible.
  • Keep person on their back with their head and back elevated.
  • Obtain prompt medical attention.

The chlorine safety equipment should be inspected regularly for proper operation, and everyone at the plant should be familiar with its use. A list of the equipment is as follows:

  1. Chlorine Leak Detector. The leak detector senses chlorine gas in the air of the chlorine storage and chlorinator room. Chlorine can be harmful in concentrations that cannot be smelled; the detector will sound an alarm if these small concentrations are detected. Make sure the leak detector is always operating.
  2. Compressed Air Breathing Apparatus. A breathing apparatus and spare compressed air tank are housed in a storage cabinet near the exterior chlorine storage room door.

Polymers

Polymers are stored in either 275-gallon totes or 55-gallon drums. See the chemical MSDS sheets in Appendix D for safety guidance on the polymers currently used at the Plant. If current chemicals are replaced, new MSDS should be maintained.