Well, honey, the acceptable level of coliforms in drinking water is zero. Zip. Zilch. Nada. Any presence of these little buggers could indicate contamination from fecal matter, and nobody wants a side of poop with their water. So, in short, keep those coliforms out of your H2O if you want to stay healthy and happy.
* The CGA Grade "E" quality verification level has become the specification most widely referenced for sport diving. CGA Grade "E" is generally considered to be the absolute minimum acceptable breathing gas quality for SCUBA diving, and many consider it to be too liberal. Filling an "Oxygen Clean" cylinder with CGA Grade "E" will introduce hydrocarbon contamination such that the cylinder is no longer considered O2 clean and may not be used for partial-pressure blending.* "Oxygen-Compatible" is CGA Grade "E" with reduced maximum acceptable carbon monoxide, hydrocarbon and particulate levels. The International Association of Nitrox Divers (IANTD) and American Nitrox Divers International (ANDI) created this designation for gases used in technical diving and gas blending. The U.S. Navy and the American Academy of Underwater Sciences (AAUS) have also issued "Oxygen-Compatible" specifications. All the "Oxygen-Compatible" specifications are similar but not identical. For the purposes of this discussion we'll use the IANTD "Oxygen-Compatible"
The "acceptable noise level" will depend on your specific needs! What is "acceptable" in one situation, may be utterly unacceptable in another.
A decision based on what constitutes an acceptable level of risk
The acceptable water quality level for coliform bacteria in drinking water is zero colony-forming units (CFU) per 100 milliliters as specified by the US Environmental Protection Agency (EPA). The presence of coliform bacteria indicates possible contamination from fecal matter and poses a health risk. Drinking water should be regularly tested to ensure it meets this standard.
It depends to the acceptable risk level in your company. Usually AFR=10 is acceptable in most companies.
Type of decontamination that is carried out by a unit to reduce contamination equal to natural background or to the lowest level possible.
Couple percents.
AQL - acceptable quality level
Type of decontamination that is carried out by a unit to reduce contamination equal to natural background or to the lowest level possible.
There are no prerequisites to be a scuba diver, you just need to have the money. You do need to take a swimming test, but this isn't too hard. even a lousy swimmer can complete it.
its the scuba tank on the swimming guys back.