Based on an analysis of nutrient data, NEON has determined that the method detection limits (MDLs) required of the external laboratory for surface water and groundwater nutrient analyses are too high for many sites. Over 10% of reported nutrient data were below the detection limit for many sites.
Currently, sub-samples for nutrient analysis are being frozen and stored for future analysis using a method with a lower MDL. The analysis of these frozen nutrient samples will take place following procurement of a new contract with lower MDLs, which may take several months. An update will be provided by April 20th, 2021.
This delay impacts the following analytes: nitrate plus nitrite as nitrogen (NO3+NO2 – N), nitrite as nitrogen (NO2 - N), ammonium as nitrogen (NH4 - N), orthophosphate (Ortho - P), total phosphorus (TP), and total dissolved phosphorus (TDP). Total dissolved nitrogen (TDN) and total nitrogen (TN) are not impacted by this delay and will be analyzed and published as expected.
Users should refer to the swc_externalLabSummaryData table, which is part of the expanded package for both Chemical properties of surface water (DP1.20093.001) and Chemical properties of groundwater (DP1.20092.001), for details of laboratory method detection limits associated with date ranges for previously analyzed data.
Please use the Contact Form for further inquiries; please select DP1.20093.001 (for surface water) or DP1.20092.001 (for groundwater) in the Data Product drop-down list and include the term "RITM0030592" in the body of your request.