Since 1986, the National Oceanic and Atmospheric Administration (NOAA), through its National Status and Trends (NS&T) Mussel Watch Program, has monitored our coastal waters for chemical contaminants and biological indicators of water quality. The Mussel Watch Program (MWP) is based on the collection and analysis of indigenous bivalve mollusks (oysters and mussels) and sediment. Mussels and oysters are sessile organisms that filter and accumulate particles from water; thus, measuring contaminant levels in their tissue is a good indicator of local chemical contamination. Currently, there are approximately 300 core MWP sites along the nation’s coast, including the Great Lakes, Hawaii and Puerto Rico. Detailed descriptions of MWP monitoring sites are available elsewhere (Lauenstein et al., 1997) and a revised version is in preparation. Initially, the MWP sites established in areas intended to represent general conditions of broad coastal areas, thus sites are not located near specific pollution outfalls such as water treatment plants or industry. In recent years however the MWP has expanded to meet a broader mission and has included sites in areas known to be directly impacted by outfalls and/or known pollution sources. These new sites provide our partners and stakeholders data that permit direct measurement of management action or remediation effectiveness. This document describes in detail the procedures used by MWP for bivalve and sediment collection. It is intended for use by NOAA staff and its partners who do the planning and execution of field collection activities or provide oversight of the staff and resources required. The NS&T Program is committed to providing the highest quality data to meet its statutory and scientific responsibilities. To assure good data quality, the MWP’s sampling methodologies are based on quality assured practices described in Environmental Monitoring and Assessment Program’s (EMAP), coastal assessment quality assurance project plan (EPA, 2001). Information in the document is presented in chronological order, so as to be of practical use to the field crews. Procedures for bivalve collection and sediment sampling are described in separate sections. Field crews may be tasked with collecting sediment only, bivalves only or both sediment and bivalves depending on the predetermined mission goals.