Electronic Report 52 Bank Parade Burnley BB11 1TS Phone 01282 414649 / 458410 Our Ref: Hollin Way/BB4 8LB/PRA/L.14 Date: 27th May 2014 Hallmark Developments (NW) Ltd Copy to: Nigel Longshaw Hallmark Court AJ Cocker Associates 132 Manchester Road [email protected] Rochdale 01706 764880 OL11 4JQ PROPOSED HOUSE LAND AT HOLLIN WAY, RAWTENSTALL, BB4 8LB PRELIMINARY RISK ASSESSMENT (DESK STUDY) INTRODUCTION It is proposed to build a detached house. The objective is to carry out a desk study, supplemented with a walk over survey, to form a Preliminary Risk Assessment (PRA) to consider contamination, landfill gas and geotechnical issues. SITE DESCRIPTION The site is an almost rectangular plot, about 28 by 15 metres, located at the north end of Hollin Way in Rawtenstall and centred on OS Grid Reference 381230 424040. The site was inspected on 21/5/14. The site is an undeveloped plot of land with a footpath going from south of the site to the northwest. The rest of the site is unkempt grass, weeds and plants. There are no signs of contamination or contaminative uses. The site is generally level but the general slope in the area is down to the west. The site is on the edge of a residential area having houses to the east and west with fields to the north. 2 TREES There are four deciduous trees to the southwest these ranging from 5 to 8 metres high. To the northwest there are 3 deciduous trees about 12 to 15 metres high. Along the north boundary there were four deciduous trees from 9 to 15 metres. This is not an accurate arboricultural survey. PROPOSED DEVELOPMENT It is proposed to build a detached house. There will be a short driveway to the front (south) and surrounding gardens. LEGAL/COPYRIGHT Material may be included in this report from Ordnance Survey (Licence No. AL100031635), Landmark, Environment Agency, Coal Authority and others. It may be copyright and the usual restrictions apply. This report can only be relied upon if the invoice has been paid promptly and in full. This report may be signed by an individual, but only on behalf of Worms Eye Limited. This report is referred to as a “Desk Study” but also involves a site inspection. Alternative names for such reports are “Phase I Report” (Phase II being the intrusive work involving boreholes etc.) or a “Preliminary Risk Assessment” (PRA). DATA SOURCES The following data sources have been viewed in compiling this report. o BGS, Geology Map, 1:50000 scale, Sheet 76, Rochdale, Solid and Drift Edition o BGS, on-shore boreholes scans (no nearby records) o Coal Authority, Interactive Mapping Data o Environment Agency, What's In Your Backyard o Groundwater o Landfill Sites o Pollution o Landmark Envirocheck Report, 9/5/14 o Ordnance Survey, Historical Maps, 1:10000 and 1:2500 scale o Walkover Survey, 21/5/14 3 ENVIRONMENTAL DATA A Landmark Envirocheck report has been obtained for the site and geological maps have been reviewed, the following is a summary of the combined data. The Envirocheck report indicated none of the following within 250 metres: Contaminated land register entries Discharge consents Water abstraction points Source protection zones Radioactive sites Landfill or other waste sites Hazardous substances sites Fuel stations Sensitive land uses Geology of Site The geological map indicates that the underlying solid rocks are sandstone of the Holcombe Brook Grit horizon in the Marsden Formation of the Millstone Grit Group, dipping to the northeast. Surface drift is shown as glacial till (boulder clay) of unspecified thickness and natural subsidence hazards are shown as very low to no hazard. Surface Water (Hydrology) A stream issues 240 metres west, flowing west to Limy Water (GQA Grade B) 270 metres west. The nearest pollution incident was a significant incident 222 metre west of diesel in Limy Water* The nearest area of flooding from rivers is shown to be 241 metres west, i.e. well clear of the site.* The area slopes down to the southwest, the flow of surface water is expected to be in this direction. * not relevant due to distance/severity/significance Groundwater (Hydrogeology) The solid rocks under the site are indicated as a Secondary A aquifer. Superficial (drift) deposits are shown as unproductive strata with a low permeability. Groundwater flow is likely to follow the topography and move to the southwest. 4 Radon Less than 1% of homes in the area are above the radon action level and radon protection measures are not required. Mining The Coal Authority interactive mapping shows that the site is not in a ‘Development High Risk Area’. Nearby Industry No trade directory entries within 50 metres, the closest entries between 50 to 100 metres being houses with either small cottage industries or the registered addresses of businesses. SITE HISTORY Date On Site Off Site Limy Water 270m west 1849 Undeveloped field 1: 10560 Generally undeveloped – poor mapping Fields to the north Houses 20m southwest and 40m west 1893 Undeveloped field 1: 2500 Grange Works (disused) 240m southwest. Farm 40m northwest 1911 - 1963 No change No change 1: 2500 1993 No change Housing estates built to the east and southwest. 1: 2500 2014 No change No relevant change 1: 10000 DISCUSSION Contamination The site is a previously undeveloped plot. There has been no use of the site from which contamination would be expected. There have been no nearby land uses, industrial or other, which will affect the site and no pollution incidents on or close to the site. The proposed development will be a house with gardens. However, there are no indications that contamination will be present at levels which will pose a risk to householders. A negligible risk is anticipated from contamination. 5 Controlled Waters There is an underlying Secondary A aquifer beneath low permeability clay. The nearest water course is a stream 240 metres west, leading to Limy Water 270 metres west. Although the gardens will allow rainwater to pass through the surface soils, significant contamination is not anticipated. Furthermore, the underlying clay will impede the migration of water and no risks to controlled waters are expected. Ground Gas There are no landfill sites or significant filled features, within 250 metres of the site, and peat is not expected. There are no nearby sources of ground gas and no risk to the development from ground gasses. Radon Radon protection measures are not required. Flooding The Environment Agency maps show that this site is clear of flooding from rivers. Flooding can occur for many reasons other than those dealt with by the EA maps. These include: burst pipes blocked drains, sewers and culverts inadequate drainage cloudbursts/flash flooding overwhelming normally satisfactory drainage systems Statements in this report such as ‘clear of flooding/flood plain’ and ‘flooding – no further action’ are references to the EA river and sea flood maps and are no guarantee that flooding will not occur. Foundations The geological map suggests that the site is underlain by clay. If present this often provides a good bearing strata for strip foundations. If clay is present plasticity tests will be required to establish its shrinkage potential, to ensure foundations are below the possible effects of tree root action. INDUSTRY PROFILE The site has had no industrial use and there have been no nearby industrial sites. 6 CONCEPTUAL MODEL A conceptual model based on the source-pathway-receptor concept is included with this desk study to show the potential pollutant linkages with this site. Likely Source Receptors Pathway Pollutant Linkage Construction workers Inhalation No Asbestos End-users Inhalation No Construction workers Short-term direct contact, inhalation of dust, ingestion No Direct contact, ingestion, from home grown vegetables, Householders No inhalation of dust Inorganic contaminants Service pipes Seeping into drinking water pipes No Groundwater Leaching towards No River/stream Leaching towards No Sulphate Building fabric Concrete directly in contact with soil No Construction workers Short-term direct contact, inhalation of dust, ingestion No Direct contact, ingestion, from home grown vegetables, Householders No inhalation of dust Hydrocarbons Service pipes Seeping into drinking water pipes No Groundwater Migrating towards No River/stream Migrating/leaching towards No Construction workers Short-term inhalation No Hydrocarbon vapours Householders Inhalation of vapours indoors and outdoors No Landfill gas End-users - in buildings Seeping into buildings, explosion, asphyxiation No Radon End-users - in buildings Seeping into buildings No CONCLUSION Contamination Taking into account the history of the site and surrounding area it is considered unlikely that contamination will be present on site and no risks are expected to householders. The development will probably require excavated material to be disposed off-site. The receiving waste site, may require confirmation of contamination levels in the soil. With this in mind the developer may consider a limited investigation, comprising two to three tests (depending on volume of material for disposal), for a general suite of contaminants including heavy metals, sulphate, PAHs, TPHs and asbestos. 7 Controlled Waters Significant levels of contamination are not expected and no risks to controlled waters are anticipated. No further action is required. Ground Gas There are no nearby sources for ground gases and no further action is required. Radon Radon protection measures are not required. Flooding The EA maps indicate that the area is clear of flooding