The improvements to Deephams Sewage Works are needed to meet European and national standards for water river quality which the current works cannot meet.
The new discharge permit has been set by the Environment Agency to meet these standards and will improve water river quality and biodiversity in the River Lee, Lee Navigation and Salmon’s Brook, into which the treated wastewater from Deephams flows.
We are committed to working with environmental regulators and stakeholders to identify potential environmental impacts of the upgrade, and to take action to manage and limit these impacts wherever we can.
How we will assess our impact on the environment
To help us identify and manage the positive and negative effects of building and using the upgrade we are carrying out an Environmental Impact Assessment (EIA). An EIA is a way of predicting and evaluating the environmental effects of a proposed development in order to help organisations, such as local planning authorities, decide whether or not the proposal should go ahead.
The EIA allows us to understand the environment around the work site and identify the likely effects the upgrade may have on the following environmental areas:
- Air quality
- Archaeology and heritage
- Landscape and views
- Flood risk
- Water resources and water quality
- Contaminated land
Understanding the possible environmental impacts will allow us to change the design of the upgrade, wherever practical, to avoid or reduce any negative effects. If there are any negative effects that cannot be avoided in practice, we will work out where and when we need to do things differently to reduce these effects, as far as is practical.
How we are going to reduce the impact of the upgrade on the environment
The Environmental Impact Assessment (EIA )will identify any measures we need to use on site during construction and operation of the upgraded sewage works to reduce any impacts on the environment.
We have carried out surveys in and around the sewage works to understand the existing environment. These include wildlife surveys (such as breeding bird and reptile surveys), traffic, noise and air quality surveys. We have also received information from other local organisations to increase our understanding of important environmental issues in the local area.
We will need to replace some of the existing structures on the sewage works and build new tanks and equipment, which will mean there will be more lorries and other vehicles entering and leaving the site. We could also create more dust and noise when we build the new tanks.
The new sewage works will re-use the existing foundations of some of the tanks, but we will need to disturb some parts of the site that have not been developed before. This means we could also disturb archaeology or affect areas containing wildlife. We will identify the significance of these impacts through the EIA process.
We will manage these impacts during construction by having an Environmental Management Plan in place, which will set out the main environmental issues that the construction team need to be aware of and the measures we need to put into place to avoid or minimise effects on the local area.
Some examples of how we will do this, include:
- Using site fences as barriers to prevent noise and dust from escaping the site
- Keeping vehicles and roads clean and well maintained
- Turning machinery off when not in use
- Keeping noisy equipment as far from residential areas as possible
- Arranging deliveries to site only when they are needed to reduce traffic movements and avoid large stockpiles of material on site for long periods
- Checking for any archaeologically important or sensitive areas before construction starts.
There will be a separate waste management plan to control and monitor the waste we produce during construction and to encourage reuse and recycling of materials wherever possible. We will also have a specific odour management plan in place to control any smells that could be created when we are replacing the old sewage tanks, and once the new plant is working.
Once the upgraded sewage works is operational, levels of traffic will be similar to now. We are developing a plan to improve wildlife living on the site after the upgrade is completed, including planting new trees and shrubs.