May 2019 – StormTac

Updated standard concentrations for the sum of PAH16 and…

26 May, 20194 July, 2019

Updated standard concentrations for the sum of PAH16 and individual PAHs, especially for rural areas

Updated values for standard concentrations for stormwater and base flow for PAH16 and respective individual PAHs for all rural types of land use such as woodland and meadows etc. and also for allotment area. Many values were previously stated as 0 in concentration for the individual PAHs, which have now been updated with estimated concentration data, which is lower than for other land uses, but this will give slightly higher estimated total concentrations and loads than before if these land uses are used.

The updated concentration data are marked in the database and implemented for new projects that are started as from 2019-05-27.

News

Calculation of acceptable concentration from development areas

16 May, 20194 July, 2019

Calculation of acceptable concentration from development areas

Based on calculated acceptable load (kg/year) and calculated flow, an acceptable concentration (µg/l) from the area is also calculated, which can also be used as a limit value. It is possible to check an outlet concentration after measures and compare with this limit value, which can give answers to whether the acceptable load is achieved for the area or if additional measures are needed.

This calculated acceptable concentration requires a recipient calculation, with input of area/land use in the recipient watershed area, and also inputs of area and volume of the receiving water, with advantage also measured concentration data from the receiving water body (see the guide).