Potable water diver
A potable water diver works in a potable water tank performing inspection and cleaning tasks.
Certified commercial divers can inspect water storage tanks, towers and clearwells without draining them or taking them out of service. SCUBA certification alone is insufficient, and additional training is required. The American Water Works Association publishes a technical standard, C652, that outlines recommendations for divers in potable water facilities.[1] The diver is totally encapsulated (no part of the divers body touches the water) in a sealed drysuit and then washed down with a 200ppm chlorine solution prior to entry into the tank. All diving dress is to be used exclusively in drinking water. This meets American Water Works Association (AWWA) standards for entering a public water system. The diver is then able to move about the tank to perform inspections or clean the tank. AWWA recommends removing sediment accumulations over 1/2" deep from the floor of a drinking water tank because it can harbor bacteria and/or other contaminants which could adversely affect water quality. Using a specially equipped pump or airlift system the diver is able to remove the loose sediment without damaging painted surfaces. This allows the chlorine in the system to more effectively do its job. Divers are an effective means to clean and inspect potable water storage tanks because all of the maintenance can be done while the tank remains in-service and full of water, and most of the interior surfaces of the tank can be easily accessed.
Diving in a tank presents hazards, particularly in water tanks above ten million litres. Divers require confined-space training and working at heights certification. Diving operations require at least one trained spotter to observe surface bubbles (indicating the diver is still breathing). The diver should be wearing a harness, strapped to a safety rope, so that in case of an emergency the spotter can pull the diver up. Divers always need to check the safety legislation in their state/country.[2]