An
approved air-gap separation or reduced pressure principle backflow
prevention assembly shall be installed at the service connection or
within any premises where, in the judgment of the Water Purveyor or
the Missouri Department of Natural Resources, the nature and extent
of activities on the premises, or the materials used in connection
with the activities, or materials stored on the premises, would present
an immediate and dangerous hazard to health should a cross connection
occur, even though such cross connection may not exist at the time
the backflow prevention device is required to be installed. This includes
but is not limited to the following situations:
1.
Premises having an auxiliary water supply, unless the quality of
the auxiliary supply is acceptable to the Water Purveyor and the Missouri
Department of Natural Resources.
2.
Premises having internal cross connections that are not correctable,
or intricate plumbing arrangements which make it impractical to ascertain
whether or not cross connections exist.
3.
Premises where entry is restricted so that inspection for cross connections
cannot be made with sufficient frequency or at sufficiently short
notice to assure the cross connections do not exist.
4.
Premises having a repeated history of cross connections being established
or reestablished.
5.
Premises, which due to the nature of the enterprise therein, are
subject to recurring modification or expansion.
6.
Premises on which any substance is handled under pressure so as to
permit entry into the public water supply, or where a cross connection
could reasonably be expected to occur. This shall include the handling
of process waters and cooling waters.
7.
Premises where materials of a toxic or hazardous nature are handled
such that if backsiphonage or backpressure should occur, a serious
health hazard may result.