GENERAL METHOD STATEMENT - Crawley

1 Page 1 03/09/2013 GENERAL METHOD STATEMENT Written By Abraham Khan Date Prepared 02/09/13 Ref. No Client Crawley Borough Council Site Name Gratton Park River Restoration Location Grattons Park Crawley Step Detail below the task to be undertaken. Describe Task: To construct a new channel for the Gatwick stream at Grattons park Proposed Start Date August 15th Completion Date TBA No of Staff Max 10 Step Identify the equipment to be used and any required permit to work. List Plant / Equip to be Used Special Requirements Test Cert. Req d? Test Cert Verified? (please initial) Permit to work Req d? Permit Issued by? (please initial) Small excavators Bio Oil/height limiter Standard excavators forward tipping dumpers Tracked dumpers Bobcat Sealed bulk tippers 20 cyd roll on roll off (RORO) skips Pressure washer bowsers Geotextile membranes Ground protection timber mats Traffic management provisions Chainsaws/strimmers/chipper Double bunded bowser Skidsteer loader Spill trays & spill kits No Welfare unit Yes Site statutory, public & site signage No Various chains / lifting equipment Yes Barrier fencing (local) No Small hand tools / equipment No Site Operative PPE No The above must be verified BEFORE work commences.

2 Page 2 03/09/2013 Step Identify the operative numbers and skills with Training/certification to undertake the task Type of Operative Required Number of Operatives Skilled Operative? Minimum Competency Required Initial when verified. Site manager/supervisor CSCS, SMSTS, 1st Aid, CIRIA Environmental Good Practice On Site or equivalent Excavator operators CPCS forward tip/tracked dumper operators CPCS Banksmen/labour CSCS Chainsaw/strimmer/chipper operators NPTC Bobcat/telhandler operator CPCS Traffic management NRSWA The above must be verified BEFORE work commences. Page 3 03/09/2013 Step List sequencing of works Instruction Accepted? (Please Initial) Scope of works covered by METHOD STATEMENT Divert footpaths Set up site fencing Set up tree protection fencing Set site compound Excavate diversion channel Tree/stump removal Top soil strip to high flow area Excavate and form new channels Remove surplus off site Perforate existing channel Fill landscaped area Riffles to channel Abutments and new bridge Divert water down new channel Fill existing channel Topsoil re-spread Remove fencing Fill inflow diversion Demobilise Page 4 03/09/2013 GENERAL Methodology Mobilisation & Site compound 2 weeks prior to the start 3 No advanced warning signs will be erected around the site to advise the public of the start date and likely duration of the works.

3 A fenced and secure site compound area will be located at the existing car park entrance area of Grattons Park. A welfare unit, toilet block and site offices will be located in this area. The height restriction barriers will be removed in order to facilitate good access for construction plant. The access is controlled by permanent three way traffic lights and therefore temporary traffic management other than local signs warning of construction traffic is not deemed necessary. Full protection is required to the existing Birch tree just north of the site compound as the stockpile area will be within the root protection area (RPA). Assume RPA to be 6m radius from the birch tree. Protection will be for the full duration of the works and include Plywood box protection to the main trunk Plywood timber ground matts (5 x 1 m x 70mm) to be placed on 150mm thick compressible material (wood chippings) on top of geotextile A wheel cleaning facility will be provided utilising a jet wash within a specified area within the compound and water collected within grips and sump/ settlement area prior to pumping to grassland to the edge of the site.

4 (in accordance with PPG5) Please see the attached sketch, Blue hatched area Site Compound. Green Hatched Line - Site Access and Egress Route Site Fencing & security Site fencing shall be erected in a manor to stop any public access into the works area and compound. This will be Heras panels, feet and double clipped. There will be H&S signs erected at strategic locations to warn of site dangers. Additional to this a motion sensor cameras will be erected in the compound area which will be linked to a 24 hour office for additional security. The Page 5 03/09/2013 police would be contacted in the case of vandalism or theft. Areas that can t be fenced due dense woodland will have extra H&S signage warning pedestrians of dangers ahead. Divert footpaths Chapter 8 pedestrian fencing and signage as per drawing 205 diverting pedestrians around the site.

5 This will be checked twice a day before and after each shift. Page 6 03/09/2013 Site Fencing & security Site fencing shall be erected in a manor to stop any public access into the works area and compound. This will be Heras panels, feet and double clipped. There will be H&S signs erected at strategic locations to warn of site dangers. Additional to this a motion sensor cameras will be erected in the compound area which will be linked to a 24 hour office for additional security. The police would be contacted in the case of vandalism or theft. Areas that can t be fenced due dense woodland will have extra H&S signage warning pedestrians of dangers ahead. Tree protection All tress that are to be retained that encroach on the works will be protected with Heras fencing around the root protection zone.

6 This will stay erected until works are completed. Tree stump removal & tree removal Tree and stump removal will be undertaken by tree surgeons using chainsaws, stump grinders and the correct PPE. This will be done to a suitable depth and back filled with subsoil. All timber that be chipped/shredded will be spread on site as agreed with the supervisor. All clearance will be in accordance with our EMP Excavate diversion channel The diversion channel will be situated not to encroach on any route protection areas (see dwg 204). A silt curtain / trap will be erected at the downstream end.(see Silt Mitigation Measures below). 360 excavators will cut the diversion channel and surplus material will be removed and stored. A strategic access will be constructed using 1200mm HDPE pipes.

7 This will be backfilled with crushed concrete and topped with Type 1 to maintain a site access. Existing bund at the north end of the flood basin to provide an overland flow path back into Gatwick Stream for flows in excess of the Mill Leat Capacity. Ensure that the Mill Leat culvert under Northgate Avenue is clear and or cut additional diversion channel back into the Gatwick Stream at a suitable location Divert Flows Prior to the channel being diverted a fish rescue team will net the live concrete lined channel from the downstream end. Once they reach the area where the temporary dam will be placed the net will fixed in a position not to let any further fish along the channel. At this time a temporary Dam will be constructed using site won clay. The clay will be placed with a 360 exactor at an angle to push the flow through the newly formed diversion channel.

8 The dam will be set at a specific height at AOD to allow overland flows through the site for flows greater than the Mill Leat capacity avoiding impacting on properties up steam. The fish rescue team will do a final net walk from the downstream end of the concrete lined channel for any remaining fish. All rescued fish will be rehomed outside of the works area downstream. Top soil strip, Excavate and form channels All site clearance will be in accordance with our EMP A silt curtain / trap will be placed at the downstream end of the new channel..( Silt Mitigation Measures below) A site engineer will set up the line and level of the excavation and top soil strip using profile boards. This will be agreed with the supervisor prior to excavation. Top soil will be stripped to approximate depth of 300mm using 360 excavators, this will be loaded into dump trucks and stock pilled for reuse.

9 All stockpiles to be located outside the proposed high flow channel The channel will be excavated from the downstream extent of the works to maintain a reasonable dry excavation. The subsoil material will be stored in a bund running parallel with the existing concrete channel ready to be reused as backfill. The amount needed to backfill the existing channel will be cubed/measured and surplus to this will be stored in a loading area to be loaded into 8 wheeled tipper lorries and removed from site. Page 7 03/09/2013 Perforate existing channels and backfill The extent of the perforation with the existing channel will be agreed on site with the supervisor. This will be undertaken with a 360 and a pecker attachment. Access to the existing Channel will be in locations to minimise the impact on any existing trees.

10 The channel will be cleared of all vegetation and soft deposits prior to backfill be placed. Subsoil will be placed by a 360 excavator and levelled in 200mm layers and compacted to maintain a stable soil structure. A silt trap/curtain will be installed at the downstream end of the channel to be backfilled. Riffles to the channels These areas will be set out by an engineer after the bulk excavation has been completed. the over dig will be approximately; Detail 1; 320MM 170 RF1 150 RF2 Detail 2; 420MM 170 RF1 250 RF3 Detail 3; 420MM 170 RF1 250 RF3 Prior to placement of the RF materials the supervisor will inspect the formation. Once this has been agreed the formation will be covered as drawing 265. Abutments and New Bridge LAWS will supply and install a timber beam footbridge.