Proposal for Northern Extension of Northolt Tunnel sift report
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- Bu səhifədəki naviqasiya:
- Location: Colne Valley OPTIONS CONSIDERED: Option A The Proposed Scheme as submitted in the hybrid Bill
- Above ground section between Northolt and Chiltern tunnels placed underground in bored tunnels with provision for connection spurs to Heathrow
- QUALITATIVE IMPACT DESCRIPTION and/or QUANTITIVE ASSESSMENT RATI NG
`Code 1 -
Accepted Uncontrolled when printed INTERNAL INFORMATION Northern Extension of Northolt Tunnel SIFT Report
C222-ATK-DS-REP-020-000034 Revision – P06
Page 51
Uncontrolled when printed INTERNAL INFORMATION
Key Sustainability Issue Topic STAGE: Constructio n or Operation EDA Considered (incl. Topic and Ref no.) Comment QUALITATIVE IMPACT DESCRIPTION and/or QUANTITIVE ASSESSMENT RATI NG QUALITATIVE IMPACT DESCRIPTION and/or QUANTITIVE ASSESSMENT RATI NG QUALITATIVE IMPACT DESCRIPTION and/or QUANTITIVE ASSESSMENT RATI NG Negligible impacts related to dust emissions have been identified. Op
No operational impacts o No operational impacts o As Option B. o Sound and vibration Const
SV1 Construction noise impacts which generate significant effects have been identified at Denham Grove (De Vere Hotel), HOAC and Denham Waterski Club. Construction traffic on Harvil Road and B467 Swakeleys Road is likely to cause noise impacts on adjacent residential and non-residential receptors, which is deemed to be significant. o The construction of the tunnel would significantly reduce direct noise impacts on dwellings compared to the Option A. Although there would still be some localised and short term sound and vibration issues for property directly over the alignment of the tunnel during construction and close to the vent shaft sites and the 700m ‘gap’. However, identified noise impacts as a consequence of construction traffic for Option A would remain as construction traffic is not predicted to decline in numbers as a consequence of this option. Construction noise impacts from the tunnel portals are not likely to change in magnitude but are likely to occur over an extended time period. + As Option B. + Op
Significant noise effects identified at South Ruislip (inc. 55 minor & 140 moderate impacts), Savay Lane (6 minor and 7 moderate impacts), Wyatts Covert (66 minor and 16 moderate impacts)and Denham grove (3 minor and 2 moderate impacts) – also the De Vere Hotel. o Operation of the route in tunnel would remove all impacts identified for Option A. +++ As Option B. +++ Community integrity Const
CO1, CO3, CO4,
CO10, CO11 Three buildings associated with the Hillingdon Outdoor Activity Centre (commercial properties) will be demolished. The lake used by the centre will be closed during construction works (a period of five years). This considered to be a major adverse effect and is therefore significant.
Users of Denham Waterski Club would be impacted during construction as a result of in-combination impacts upon amenity including noise and visual impacts for a period of approximately one and a half years. The combination of these effects is considered to result in a moderate adverse effect and is therefore significant.
In combination impacts from traffic, air quality and noise would be experienced by properties on the B467 Swakeleys Road. The combination of these o There would be no demolition of buildings associated with community resources or residential properties identified in the base case. HOAC and Denham Water Ski club would remain operational through the construction period. 1.1.9 Potential for in-combination impacts on properties on B467 Swakeleys Lane to remain, depending on routes for spoil removal.
+++ As Option B. +++ `Code 1 -
Accepted Uncontrolled when printed INTERNAL INFORMATION Northern Extension of Northolt Tunnel SIFT Report
C222-ATK-DS-REP-020-000034 Revision – P06
Page 52
Uncontrolled when printed INTERNAL INFORMATION
Key Sustainability Issue Topic STAGE: Constructio n or Operation EDA Considered (incl. Topic and Ref no.) Comment QUALITATIVE IMPACT DESCRIPTION and/or QUANTITIVE ASSESSMENT RATI NG QUALITATIVE IMPACT DESCRIPTION and/or QUANTITIVE ASSESSMENT RATI NG QUALITATIVE IMPACT DESCRIPTION and/or QUANTITIVE ASSESSMENT RATI NG effects will result in a major adverse effect on the amenity of residents along this route, which is significant. Op In combination noise and visual impacts for 5 properties next to Denham Grove (De Vere Hotel). 1.1.10
Should HOAC remain post-construction the use of the lake would be restricted and noise and visual impacts would affect the amenity for users of the facility.
o There would be no impact on any of the community facilities or residential properties identified in the base case. +++ As Option B. +++ Transport accessibility / severance Const TT1, TT3, TT4, TT7, TT9 Construction of the Proposed Scheme is forecast to result in changes to daily traffic flows due to construction traffic, road closures and diversions. Delays to vehicle users and congestion is predicted for the following junctions: • A412 North Orbital Road with Denham Green Lane (major adverse effect); • B467 Swakeleys Road with Harvil Road (moderate adverse effect); and • A40 Western Avenue with B467 Swakeleys Road (moderate adverse effect).
Temporary closures of Chalfont Lane and Tilehouse Road would have an adverse impact on vehicle occupants due to the increased travel time associated with the length of the diversions, resulting in a major adverse effect on vehicle occupants.
Construction of the Proposed Scheme will result in substantial increases in traffic flows (i.e. more than 30% for HGV or for all vehicles) and these will cause an increase in traffic related severance for non- motorised users at a number of locations generating moderate and major adverse effects.
There will be moderate adverse effects on non- motorised users due to length of temporary PROW o There would be no significant impacts on the cycle routes or bridleways identified in the base case. Rickmansworth bridleway 004 would be diverted permanently as it currently lies across the proposed open gap at Ch 30+500, giving a minor adverse impact
The provision of a ‘gap’ structure in the vicinity of the M25 allows the Chiltern and the extended Northolt tunnel to be bored from the main works compounds, enabling works and processing area for excavated materials to take place at the same location as the ‘base case’ option.
However, with the bulk of the Proposed Scheme now in tunnel, the volume of excavated materials generated would be substantially higher; conversely the requirement for engineering fill and mitigation earthworks is far lower. As a consequence, the bulk of the excavated tunnel material from the Chiltern tunnels, the ‘gap’ structure and the new section of tunnel is likely to be treated as surplus to project requirements. Material from the extended Chiltern tunnel,700m gap structure and the extended Northolt Tunnel from Shaft F will be removed from site via M25 and then onwards to the ultimate destination for disposal. The volume of surplus excavated material needing to be taken off-site for third party disposal, or beneficial re-use would increase to 4.22million m3 as a consequence of Option B when compared to Option A.
This would result in an additional --- As Option B, although the slight reduction in spoil removal would have a consequential reduction in HGV traffic. However, the additional traffic generation would be significantly greater than Option A. ---
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