PLSO The Oregon Surveyor Sept/Oct 2020

20 The Oregon Surveyor  | Vol. 43, No. 5 Featured Article There will be points where little to any- thing is known. I have seen where the septic tank was a VW bus and plans did not exist for the entire property. There are also former industrial areas where every building was demolished. There may not be plans, but if there are, they do help locators. How Do Locators Find Stuff, Anyway? When they are available, locators start by looking at maps or prints. This gives them an idea of what should be in the area. They also look over the area for features that indicate buried facilities. These could be light posts, utility boxes, valves, clean-outs, saw-cuts, and asphalt patches, among many other things. Logic and experience also develop an expec- tation for the site. Based on what they see, they determine hook up points and go to work. The vast majority of utility locating is done by electronic means. A transmit- ter sends a signal down a conductive line and a receiver detects its location. Metal pipes, electric wires, and most commu- nication lines are conductive. Lines that are not conductive are supposed to be buried with a tracer wire. This includes PVC pipes, poly gas lines, and some fiber optics. Some PVC, concrete, or tile drain lines can also be located by inserting a sonde or running a fish tape down the line. (The camera that plumbers use to inspect drain lines contains a sonde to give location and depth.) Locating by measure is also frequent- ly used. This requires good records and is the primary method that municipali- ties use to mark sanitary sewer laterals. The locator has maps made from both as-builts and camera inspection reports. The line is marked by measuring off the footage from the center of a manhole. The letters SS UL are frequently found next to the lateral mark. This stands for Sanitary Sewer UnLocatable. This is their way of noting that it was marked by measure, not by electronic methods. Sometimes a gas poly service may also be marked by measure when the loca- tor is unable to access the meter. Again it should be noted on the ground if it was marked by measure. A very simplemethod of locating is by line of sight. This is when you can see both This excavator called for private locates after exposing a private fiber optic cable. Dousing rods were used to find this septic system. It was abandoned in 1957, but its location needed to be determined for dividing a lot. continued from previous page T