Wastewater Discharge Modelling Case Study
Project: Wastewater discharge modelling
Client: Montgomery Watson Harza / United Utilities
The Challenge
Bathing water along the Cumbrian coast was failing to meet the required standards. United Utilities therefore needed to devise and implement an improvement scheme, involving the combination of some discharges and potentially locating some discharge points further from shore. In order to select the most cost effective solution the United Utilities needed to:
- evaluate the different proposed schemes against the current discharge regime;
- determine the extent to which overall bathing water would be improved by the various alternatives; and
- predict local water quality impacts due to combination and relocation of discharges.
The Solution
Working closely with the client, we were able to:
- Rapidly produce a detailed numerical model of the discharge area using the well respected MIKE21 two-dimensional depth averaged model for coastal waters;
- Simulate the effects on water quality both in base flow and storm flow conditions for the proposed discharge regimes;
- Compare the resulting predictions of faecal coliform concentrations with guideline concentrations to assess compliance of each alternative with the required standards.
The Benefits
Our use of the MIKE21 coastal model:
- eliminated the need for the client to carry out expensive tracer studies;
- allowed the client to compare the performance of alternative schemes and discharge regimes;
- enabled the client to implement a cost-effective scheme which produced real improvements in water quality.