NRSA data 2000-2014 Deposition Largest N Source Lin et al.
NRSA is part of EPA’s National Aquatic Resource Surveys which samples different surface waters on a 5-year cycle during the growing season. For logistical reasons, each NRSA cycle occurs over 2 years. Since nonwadeable systems were not sampled during the initial 2000–04 survey, we restricted our analyses to systems …