Edition 52 // February 2019 Tech Tips by NAsscO is A bi-mONThly ArTicle ON TreNds, besT prAcTices ANd iNdusTry Advice frOm NAsscO's TreNchless TechNOlOgy membership prOfessiONAls. IdentIfyIng and ClassIfyIng a true MIsCellaneous Water level sag By NASSCO Member Michael P. Kerr, NASSCO Training Director Beginning of the Sag End of the Sag Depth of water at the deepest point