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).
Brook trout have few aquatic predators because few piscivorous (fish-eating) fish live where they do. Larger trout, especially brown trout, eat smaller brook trout.They are more likely to be eaten by such fish-eating birds as herons, and kingfishers.Otters and snapping turtles also prey upon them.he food of the young brook trout is mostly small insects. Older fish eat larger invertebrates including many types of aquatic (water) insects, sideswimmers, snails, and worms.