The NFPA 70E Standard details multiple levels of Hazard Risk Categories (HRC) [see table 1.1], also called Levels. The greater the risk: the higher the HRC. Arc Rating is the factor that indicates which HRC is necessary, and can be measured in either ATPV or EBT.
The optimal pH range for brook trout appears to be 6.5-8.0,with a tolerance range of 4.0-9.5.Brook trout occur in waters with a wide range of alkalinity and specificconductance, although high alkalinity and high specific conductance usuallyincrease brook trout production (Cooper and Scherer 1967).
These fish are called sea-run trout, salters, or coasters and are considered anadromous, similar to salmon. These fish also lose much of their color, taking on a more dull silvery hue. Spawning of wild brook trout occurs in autumn in gravel beds in the shallows of stream headwaters.