February 10, 2022 by Adam Peters


A lack of monitoring data for Dissolved Organic Carbon (DOC) is often a limiting factor in implementing bioavailability-based Environmental Quality Standards for trace metals such as copper, nickel, and zinc. Some limited evidence from the UK has suggested that dissolved iron concentrations can provide an indication of DOC levels where no other sources of data exist.

A recent publication from a research group at the University of Architecture, Civil Engineering and Geodesy in Bulgaria has looked at the best ways to overcome this problem with relatively limited datasets of some parameters like DOC, TOC (Total Organic Carbon), and dissolved iron are available. The study used user friendly bioavailability tools, including bio-met to assess bioavailability and established a hierarchy of approaches for estimating DOC concentrations for a particular water body where no actual monitoring data were available. This uses measured TOC data if available, and waterbody or regional default values.

By following this approach, it is possible to identify specific regions where additional targeted monitoring is required to properly assess compliance with EQS for metals in the future.