Significant Industrial User. Any industrial user that: discharges an average of 25,000 GPD or more of process wastewater to a POTW; contributes a process waste stream that makes up 5 percent or more of the average dry weather hydraulic or organic capacity of the POTW; is designated as such by the Regulatory Authority on the basis that the industrial user has a reasonable potential for adversely affecting the POTW's operation or for violating any pretreatment standard; or is subject to federal pretreatment standards under 40 CFR.

specialist spinal injury unit.

Special Investigation Unit; an investigation division of an insurance company.

Special Incident Unit

Section of Independent Utility