NP&V utilizes a Geophysical Survey Systems, Inc. (GSSI) SIR-3000 Ground Penetrating Radar (GPR) unit to locate underground structures and perform subsurface geophysical surveys. Specifically, the GPR unit is utilized to located subsurface sanitary systems structures (i.e. cesspools, septic tanks, grease traps, etc.), associated piping and underground storage tanks. The GPR unit can locate most underground utilities; however, this unit is not a substitute for private mark-out of utilities. A pipe camera with a color monitor and 200 foot long cable, a locating head and/or flushable locating device are utilized to locate subsurface sanitary systems and stormwater leaching pools. NP&V operates a magnetometer when appropriate to locate subsurface ferric steel objects. The combination of these tools allows NP&V to complete flow studies to determine system interconnection and discharge often needed for system closure, sampling and in response to agency requests.