AA/3/A UNITED UTILITIES WATER LIMITED (ECCLES WASTEWATER TREATMENT WORKS) COMPULSORY PURCHASE ORDER 2016 PROOF OF EVIDENCE ON BEHALF OF THE ACQUIRING AUTHORITY IN RESPECT OF WATER QUALITY DR KEITH HENDRY FIFM CENV, APEM LTD MAY 2018 1 1. Qualifications, experience and scope of evidence 1.1. I am Dr Keith Hendry, Chairman of the science based aquatic consultancy firm APEM Ltd based in Manchester. I am an aquatic scientist with over 30 years’ experience in water quality and freshwater ecology/fisheries. I have specific expertise in relation to the Manchester Ship Canal (MSC) and urban waterways in general. I was the Scientific Advisor to the Mersey Basin Campaign and its successor organisation, the Healthy Waterways Trust, for 25 years (renamed the Mersey Rivers Trust), becoming a trustee in 2016 and elected Deputy Chairman in 2017. The Mersey rivers, Salford Quays and the MSC have all featured heavily in my long involvement with the Campaign and Trusts. 1.2. I have a Bachelor of Science Degree in Biology (specialising in Fish Biology) from Plymouth Polytechnic and a PhD from Manchester University awarded in 1991 on ‘The Ecology and Water Quality Management of Disused Dock Basins and their Potential for Alternative Uses’. I am a Fellow of the Institute of Fisheries Management and a Chartered Environmentalist. I have published over 40 scientific papers in peer reviewed journals and conference proceedings, many of which relate to the MSC. 1.3. From 1987 to March 2018 I was Managing Director of APEM Ltd, previously having worked for South West Water Authority. Over these 32 years at APEM I oversaw the company’s development into one of Europe’s leading specialist aquatic science consultancy firms, now employing over 100 scientists. In March 2018 I changed roles to become Chairman of the APEM board, responsible for the strategic development of the firm. 1.4. My work on the MSC dates back to 1987 and continues to the present day. My PhD from Manchester University, based largely on the water quality and ecological transformation of Salford Quays, involved extensive scientific investigation into the MSC and its dock basins. I have undertaken many consultancy commissions and over 30 research projects on the MSC, including in relation to: water quality characterisations; artificial water quality management using large scale oxygen injection; sediment contamination and the influence of bed sediments on water quality; and long term fisheries and invertebrate investigations. Some of these studies were instigated in 1987 and remain ongoing. This has provided me with a detailed understanding of the interaction between water quality and aquatic ecology in the MSC. In particular, I have undertaken extensive studies into the impacts of United Utilities’ assets (treated 2 effluent, storm sewage, and imported water assets) on the water quality and ecological environment of the MSC, including bracket sampling around the Salteye Brook/MSC confluence. 1.5. In 2007, I took part in a major investigation into the main influences on water quality throughout the entire freshwater length of the MSC1. This study was the most detailed examination of the water quality status of the MSC ever undertaken. It investigated the factors that influence water quality, including United Utilities’ treated and storm water discharges, other discharges, the influence of sediments and the form of the MSC itself. The study concluded that the overriding factor influencing water quality (in particular the all-important parameter dissolved oxygen) was the physical structure of the MSC itself. Its artificial steep banks and deep nature facilitate rapid stagnation during dry, still weather conditions that consequently result in rapid oxygen depletion from the sediments up through the water column. 1.6. I provide this Proof of Evidence on behalf of United Utilities in relation to the United Utilities Water Ltd (Eccles Wastewater Treatment Works) Compulsory Purchase Order 2016. 1.7. The purpose of my evidence is: 1.7.1. To provide the background for the CPO Scheme from a water quality perspective; 1.7.2. To clarify the implications for the CPO Scheme in the context of changes to the Salteye Brook and changes to the MSC; 1.7.3. To explain the water quality implications of the alternative proposals now being suggested by the objectors; and 1.7.4. Consequently, to provide a response to objections raised against the CPO Scheme. 1.8. My Proof of Evidence is necessarily of a technical nature and uses a variety of technical terms and abbreviations, which are defined in the Glossary at Appendix 1. 1.9. For the reasons set out below, I consider that the proposals to which the Compulsory Purchase Order relates will be of benefit to water quality in both Salteye Brook and the MSC. 1 APEM (2007) Manchester Ship Canal Water Quality Review. Parts 1 and 2. United Utilities, APEM Scientific Report 410039, September 2007 3 1.10. I confirm that this Proof of Evidence is true and sets out my professional and honest assessment. I am aware of and have complied with my duties as an expert witness and those as a Chartered Environmentalist. 4 2. Executive Summary 2.1. Treated sewage effluent from Eccles Wastewater Treatment Works (WwTW) is currently discharged into Salteye Brook, a tributary of the Manchester Ship Canal (MSC). As a consequence, the part of the Brook below the effluent discharge point has significantly lower water quality than that upstream. 2.2. As dealt with in more detail in the evidence of Luke Pearson, the Environment Agency (EA) as the regulator has required the water quality in Salteye Brook to be improved to meet the relevant standards in the Water Framework Directive (WFD). The proposed Scheme will facilitate meeting the required standards set by the EA for Salteye Brook. It will do so by transferring treated effluent directly to the MSC adjacent to the point where Salteye Brook joins it, rather than into the Brook itself. 2.3. Eccles’ final effluent discharge currently increases mean flow in Salteye Brook by nearly 200%, and is therefore the overwhelmingly dominant source of water in the Brook. In contrast, the Eccles final effluent discharge constitutes less than 2% of the overall MSC flow downstream of Salteye Brook, and if transferred (under the CPO Scheme) directly to the MSC would therefore result in much greater dilution than is possible in the Brook. 2.4. Transferring the effluent discharge directly into the MSC in the way proposed, rather than into Salteye Brook, will lead to significantly and immediately improved water quality conditions in Salteye Brook by removing the large majority of its ammonia, biochemical oxygen demand (BOD) and nutrient contamination. Maintaining a discharge into Salteye Brook, even under the more stringent consent standards that would be required for such a discharge, would still result in lower water quality in Salteye Brook than the CPO Scheme transfer to the MSC. 2.5. Transferring the effluent discharge directly into the MSC via the pipe and outfall under the proposed CPO Scheme will achieve this substantial improvement to Salteye Brook, whilst at the same time not resulting in any material detriment to the water quality in the MSC. Indeed, by also providing greater storm flow capacity in the pipe and providing for screening of such flows, there will in fact also be an overall net improvement in the water quality of the MSC achieved by the proposed CPO Scheme. 2.6. The objection on behalf of the Manchester Ship Canal Company Ltd (“MSCCL”) and Peel Investments (North) Ltd (“PI(N)L”) assumes that Salteye Brook has an important role in cleaning the effluent water before it enters the MSC. I consider that this view is incorrect. Salteye Brook’s poor water quality is exacerbated by the 5 fact that it is a small river now flowing along the former channel of the much larger River Irwell (i.e. substantially wider and deeper compared to the Salteye Brook channel). Hence in its lower reaches it is now therefore considerably larger and slower flowing than a river of this size would normally be, with little gradient. As a consequence, the natural processes of re-aeration that would ordinarily be expected to remove contaminants from the water will not be operating to a significant extent. Currently, Salteye Brook is therefore unlikely to have any material beneficial effect on water before it enters the MSC. It may even reduce water quality further, as oxygen used to break down contaminants chemically will not be replaced. 2.7. Transferring the discharge to the MSC will result in a significantly reduced flow in Salteye Brook. However, the removal of sewage effluent inputs will more than offset any potential disadvantages of this reduced flow. 2.8. The existing and ongoing poor water quality in the MSC is significantly exacerbated by its artificially engineered physical nature (deep, steep sided and slow flowing). This inhibits mixing and replenishment of oxygen from the atmosphere, leading to periodic water quality problems mainly associated with oxygen levels. This can occur irrespective of the quality of inputs, and is particularly prevalent during periods of still, dry weather. Indeed, the physical structure of the MSC is the main driver influencing water quality under still, dry weather conditions, irrespective of any effluent discharges into it. 2.9. A major benefit of the proposed CPO Scheme is to offer a safe refuge with good water quality to fish populations in the MSC below Barton Locks during these periodic episodes of low oxygen concentration. The substantially improved oxygen conditions in Salteye Brook, which will result from removing the sewage effluent currently present, will offer an important fish refuge due to unobstructed passage between the MSC and the Brook.