EA Comments 10/10/08 on Version 2 of Ship Canal WQ Investigation Final Report

SECTION 1. EXECUTIVE SUMMARY 1. In the second paragraph opens : “United Utilities viewed this investigation…”. Suggest that this is changed to “This investigation was an opportunity to …..”

2. The first sentence of the fifth paragraph:“The canal water quality at completion of AMP4 was assessed which showed non-compliance with EC FFD standards plus near-total non-compliance with UPM Fundamental Intermittent Standards” could be clearer. Suggest :“The model predictions confirm that when all committed AMP4 schemes have been completed, there would still be non-compliance with EC FFD standards plus near-total non-compliance with UPM Fundamental Intermittent Standards”. It could also be worth adding to this paragraph that the predicted outcome that there will be compliance with 99%iles but no other standards confirms the doubts over these being the planning standard for improvements to the canal.

3. Under Study Findings & Proposed Strategy it is stated “The proposed strategy from the study shows that in theory a solution is possible in the long term. “ Delete “in theory” as discussed with Peel/MSC Co.

4. In the description of the third principle of the solution strategy , “It is recognised the reaeration would” should this refer to “aeration” rather than “reaeration”.

SECTION 2. INTRODUCTION 1. The re wording of this section still does not provide the additional explanation that was requested. This is in terms of the basis for an investigation replacing a substantive scheme in AMP4, the balance of impacts in the canal from current discharges and the sediment and sources of the sediment.

2. We have still not received three of the reports referenced. This has made making further comments on the economics assessment in particular difficult - MSC – Data Collection Report – February 2008 - MSC – Economic Analysis of Values for Environmental Improvements – March 2008 - MSC - Canal Model Build and Calibration Report – RT-NW-08-483 Rev 01 – June 2008

3. In the catchment description (Section 2.2.1) Salteye Brook should perhaps also be identified in the second sentence of the second paragraph as significant tributary (with its own ICM): “The rivers Mersey, Irwell and Bollin, plus Salteye Brook, Glaze Brook and Red Brook are the largest tributary rivers.”

SECTION 3 STATUTORY DRIVERS 1. Table 3.2.1.1 – “Report Model Results and Permitted FIS Exceedances” – shows 2 FIS failures are allowed of the 3 month return period standard when assessing data only for one year or one summer. Shouldn’t this be only 1 allowed failure over the 5 months? 2. The section 3.4.3 on the non-parametric method is welcomed but it would be useful to have a fuller explanation of the effect of using a parametric assessment on the estimate of percentiles ie that reductions expected from intervention measures were not as great as expected because of the influence of a limited number of very high results on the standard deviation which would have less effect on the rank.

SECTION 4 METHODOLOGY AND ASSUMPTIONS

1. A water quality solution for WwTW Inlet CSO and Storm tanks was in the base AMP3 programme. Drivers were removed and a delay in delivery date was recorded by Change Protocol. It is an error than that the increased FFT and storage were not included in the baseline.

2. The error in using representing Ashton STW final effluent with a 95%ile of 3mg/l ammonia rather than 6mg/l in the baseline should be mentioned and perhaps qualified in perceived implication. This should also be done for the errors for Bolton intermittents and final effluent.

3. After the explanation of the approach for final effluent quality, where this is better than required consent quality, it would also be useful to refer to AMP4 no-cost schemes where this certainly also applies i.e. for Davyhulme, , , and Macclesfield.

4. In Table B1 the NEP ammonia standards for and are for a WFD driver so should also be indicated for WFD scenarios.

5. The question on accounting for design horizons and future growth/development still needs to be answered

SECTION 5 ECOLOGICAL MODELLING

We are still uncertain about what is represented in Figure 5.2.5 [Minimum DO at the bottom of the water column in the MSC Turning Basin (Site 1) along with approximate time of introduction of various fish species to the Canal]. The minimum DO at the bed is indicated to be greater than 6 mg/l since 2005. This site a appears to correspond with APEM Site B-L8, data from which was reviewed in the calibration of the canal model. Dissolved oxygen concentrations lower than 6mg/l were recorded here. Can you clarify?

SECTION 6 ECONOMIC SURVEY

1. Concerns still remain over the conclusions and absence of any pound 1 benefits, the absence of even a description of the benefits to the wider businesses world (the WTP just looked at residents) and future developments in this area.

2. However a mean WTP of £6 per household equating to £30.9M is a significant amount. The proposal to carry out a subsequent full cost benefit assessment is not considered necessary. The concept of considering to develop a solution based on the valuation of these benefits is misguided. Such an economic survey would never capture all the benefits.

SECTION 9 SOLUTION SCENARIOS

Scenario 1

Although in the response to comments it is indicated that the text “It was accepted this was not a buildable solution but it would provide an insight into the canal sensitivity.” had been updated, this does not appear to be the case. Our suggested alternative was “The purpose of this run was to provide an insight into the canal sensitivity and establish the importance of UU assets”

Scenario 1 Model Results

The statement is made: “These improvements should also be balanced against the exorbitant cost and extensive disruption to UU customers, aside from the engineering difficulties likely to be encountered to deliver such a solution in the densely populated urban area. This would make the delivery of such a scenario infeasible. “ Please delete reference to exorbitant cost etc .

Scenario 15 Measures Detail

Although NEP requirements for Altrincham, Tyldesley and Leigh have been included in Table B1, these WwTWs have not been identified in the text here to be included in addition to Oldham, Davyhulme and .

SECTION 11 RECOMMENDATIONS

The removal of any timescales from the report is understandable but leaves the way forward a little open and uncertain. If UU do not wish to have such information in the report we would ask for a commitment to be provided in writing separately.