Samples collected between 1998 and 2002 were kept cold until filtered within several days of collection. Samples collected after 2002 were filtered in the field. Filtered samples were frozen until analysis. Samples collected prior to April 2001 were analyzed at MBL. Samples collected after April 2001 were analysed at UNH in the Water Quality Analysis Lab. Ipswich synoptic samples from November 1999, and February, April and September 2000 are correct in the month, but day of month is unknown.
Grid ID: Sites were georeferenced to a gridded river network with 120m grid sizes. Latitude and longitude reflect slight shifts to ensure proper placement on the digital river network.
Site description file for all stations sampled in WAT-UNH-IPPR-Synoptic file can be found in WAT-UNH-IPPR-Synoptic-Sites file.