East Cambridgeshire District Council Water Cycle Study Detailed ...

In summary:
Stage 2 Water Cycle Study: Final Report
Sept 2011
39
Cambridgeshire Horizons
East Cambridgeshire – Detailed WCS
• The remaining residual allocated and windfall development proposed for Bottisham should
be limited to an annual completion rate agreeable with both AWS and the Environment
Agency up to 2015; It is likely that the 50 outstanding permissions will take any available
headroom that can be identified up to 2013 and hence growth from allocations and windfalls
should not be granted permission without confirmation from AWS and the Environment
Agency that capacity is available up to 2015;
• ECDC should meet monthly with AWS and the Environment Agency to determine a suitable
annual completion rate up to 2015 until a long term solution can be determined;
• ECDC should facilitate workshops with AWS and Environment Agency to develop a long
term solution to be developed in time to implement in the next Asset Management Plan
period (2015 to 2020) to allow all remaining residual growth to take place.
New Solution Requirements – Future Good Potential
There are two wastewater catchments where Good status cannot be achieved following the
growth – these are:
• Soham (for phosphate); and
• Bottisham (for phosphate).
The modelling assessments have shown that for both Soham and Bottisham, the receiving
watercourse downstream of Bottisham could not achieve Good status without the growth and it
is therefore factors other than the proposed growth that are preventing the achievement of
future Good status. Attainment of future good status is therefore not a barrier to growth and ‘no
deterioration’ consents detailed in Table 3-3 above need only be considered in this WCS.
Ely Alternative Option
The capacity assessment for both of the Ely WwTWs indicates there is sufficient combined
capacity to accept wastewater from growth within existing consents. However, consideration is
being given to the location of a new WwTW to the north of Ely. A meeting was held between
AWS, Cambridgeshire County Council and ECDC to discuss the relocation of Cresswells Lane
WwTW on 4th October 2010. AWS is open to such a move but it is too early to make any
commitments and scheme viability is expected to be a key issue. The benefits will need to be
weighed against the costs when options for serving Ely North are evaluated. The policy position
in LDF documents will also be a consideration. AWS has therefore left the option of relocation
to Ely North open in the Minerals and Waste LDF evidence and intends to continue this position
at Public Examination.
Preliminary technical feasibility of this option has been considered in this Detailed study by
assuming a theoretical position where a new WwTW is constructed in close proximity to the
potential North Ely development sites. It is assumed that all existing wastewater flow and all
future flow from development from Ely would be transferred to the new WwTW and both Ely
Old and Ely New WwTW would be closed and discharges stopped.
The modelling has shown that, from a WFD and water quality perspective only, such an option
would be technically feasible without resulting in a downstream deterioration in current quality,
and that good status could be achieved downstream for all parameters when growth is