Environmental factor for discharge to water

Informations

Funding country

Norway

Acronym

-

URL

-

Start date

1/1/2016

End date

12/31/2019

Budget

405,082 EUR

Fundings

Abstract

Many forms of pollution pose a serious threat to natural diversity, health, water and food supply. In order to ensure sustainable management of aquatic environments, it is important and beneficial to have an objective and quantitative methodology for early identification of risk. Early detection of risk increases the possibility of taking preventive and cost-effective measures. Today, there is a requirement for industries, landfills etc. that their wastewater is mixed in to the recipient as optimal as possible, with rapid dilution. The methodology for calculating this is not standardized, and thus different descriptions of the discharge and how it is mixed in the receiving waters, varies. The assessments made e.g. the establishment of a new land-based player is therefore at risk of being made based on qualitative and subjective assessments. Better risk assessments in advance of discharges focus on risk mitigation measures and not just impact mitigation measures. The aim of the project has been to develop a model to describe the dispersion, dilution, storage and impact area from one or more discharges to a water body, so that it will be possible to make risk assessments in advance of discharges. The model developed, is a combined integral and particle tracking model. The integral model describes the initial jet stream and how it is diluted and stored in the water masses. The second part consists of a slightly modified particle tracking model, the Lagrangian Advection and DIffution Model (LADIM), developed by the Institute of Marine Research. The coupling of the two ensures that both the near- and far-field processes are resolved adequately. The modification ensures greater variability in the data by replacing a constant vertical diffusivity value with a variable and adding particle settling properties. The model collects data from Open Source hydrodynamic models with high spatial and temporal resolution for salinity, current and temperature. Empirical in-situ data can be integrated into the model. Dilution in the far-field is calculated using kernel density estimation (KDE). The model shows good results in comparison with field studies. The model can be used to simulate a single or multiple discharge. With the model it will be possible to calculate where the discharge should be released to achieve maximum dilution and distribution in the area. A method has been developed for calculating the probability of exceeding any limit values (e.g. EQS, PNEC), as well as calculations of the accumulated concentration at the measuring point between several discharges.