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 numbers were up and brown trout numbers were down, but keep in mind that browns only. make up about 6 percent of the trout population in this section of the Prairie (Gleason School Forest). About 20. percent of the brook trout are over the legal length limit of 8 inches and 5 percent are over 10 inches.