This is the first example of the work we are doing on-farm as part of TMAF Morley Clean Water project. TMAF Farm Manager David Jones provides the context, aims and the work done – using the farm’s equipment and labour – so far.
The context
“On part of the TMAF’s farm at Morley, near the village of Deopham, sewage and wastewater from 24 houses arrives on a small rural sewage treatment works owned by Anglian Water on our land. From the treatment works water is discharged into a small ditch which opens into a wetland /pond area about 90m x10m in size. From the inlet, 1.5m above the outlet, the water passed through black silty soil and a root mass of some bull rushes but predominantly nettles. Assessments in Spring 2019 showed that the water was high in ammonia and phosphate.
The problems
The water entering the sewage treatment works is more than just foul water.
More houses have extensions capturing more rainwater which means the amount of grey water entering sewage system is bigger than it ever was. Inside those homes, more washing machines and dishwashers are also delivering more water to the sewage system. Many detergents used contain phosphate which just adds to the loading of the system.
The small sewage treatment works at Deopham is overwhelmed by what it is being asked to do. As it is a small system servicing just 24 houses, it is a low priority for Anglia Water for upgrade.
TMAF Morley Clean Water Project solution
Our solution is to make this pond area more effective at holding water and capturing nutrients. Firstly, we want to slow the flow of water as it passes through the pond. Secondly, we can introduce a more diverse range of plants that will help to absorb nutrients.
Groundwork: The pond has been made into 3 connecting pools.
The first pool is relatively deep to catch sediment. Water only flows into Pool 2 through a syphon when it reaches a trigger level. Depending on the flow, it could take between a few hours and 10 days to refill to the higher level.
The point of this is to slow the flow to capture silt but also to buffer the flow so if there is a surge of water it does not immediately reach rivers and cause flooding.
Planting: Both Pool 2 and Pool 3 are to be planted with a range of plants to capture nutrients.
Measuring: The water quality and flow is going to be monitored. At some point the pools will need to be cleaned out as the plant material and silt increases.
Time and effort so far:
- 5 tonne farm digger for 2 days (@ £200/day) plus 16 hours farm labour
- Pipe (£500) and installation with 4 hours farm labour
Worth it?
It could be said that our small amount of water is not going to cause any flooding. However, with flood prevention every little helps. If many landowners take steps to reduce water surges, together we can contribute to reduction risk of flooding elsewhere.
We will be watching what beneficial differences we make to clean the water on this site and look forward to sharing the results.”