PNNL

Abstract

In many cases stormwater compliance monitoring is labor intensive, expensive, and largely unsuccessful in providing the data needed to support stormwater management goals. In addition, data from manual grab sampling and automated composite sampling are rarely collected in a manner that provides the information required to identify sources of contamination, evaluate the effectiveness of Best Management Practices, or inform effective decision making. Furthermore, monitoring is often driven by the need to meet low concentration benchmarks for metals and other constituents that do not take into account loading into the receiving waters, resulting in arbitrary monitoring requirements (monthly or seasonally) that are not tied to the driving forces within the watershed such as hydrology (flow regime), weather (storm events and antecedent dry periods), and upland land use and cover (Rosen and Johnston 2015, US Navy 2016).