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 need lots of oxygen and a water temperature of 53 degrees or colder. Because of this, Brook Trout actively migrate up and down the rivers all year looking for the right conditions. In the spring, the Brook Trout are easy to find. Any river section with a rapids or strong current will hold the trout. As the season changes into summer, the Brook Trout get ready to migrate.