East Cambridgeshire District Council Water Cycle Study Detailed ...

3 Detailed Wastewater Strategy
3.1 Stage 1 Conclusions
Stage 2 Water Cycle Study: Final Report
Sept 2011
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Cambridgeshire Horizons
East Cambridgeshire – Detailed WCS
The Stage 1 study concluded that whilst several Wastewater Treatment Works (WwTW) have
capacity to accept and treat wastewater flow from growth without any changes, several did not
including:
• Littleport WwTW;
• Soham WwTW;
• Witchford WwTW;
• Witcham WwTW;
• Haddenham WwTW;
• Burwell WwTW; and
• Bottisham WwTW.
The Outline Study concluded that these WwTW would require upgrades in order to service the
maximum growth levels proposed in the district whilst meeting the WFD and habitats Directive
water quality targets of the watercourses receiving the discharges. It concluded that solutions
need to be identified through this Stage 2 WCS.
A high level assessment of capacity in the sewer network determined whether there is likely to
be sufficient capacity to transmit additional wastewater flow generated by growth to the various
treatment works within existing infrastructure. Several locations are likely to require upgrades
to (or require new) infrastructure such as sewer mains and pumping stations including the
following locations:
• Ely;
• Littleport;
• Soham;
• Burwell; and
• Haddenham;
3.2 Wastewater Treatment Options Assessment
3.2.1 Stage 2 assessment methodology
As with Stage 1, the volume of wastewater generated from growth in each catchment was recalculated
for the new growth figures and compared to the treatment capacity at each WwTW.
If there was sufficient headroom in the existing volumetric consent of a WwTW, then the growth
can be accepted and a solution is feasible without the need for WwTW improvements. These
WwTWs were assigned a ‘green’ coding under the Red/Amber/Green (RAG) assessment; see
Table 3-1and Figure 3-1 below.