Download The VG liked this idea as anything that re

Lesson Reference No:L90
(To be entered by MP Knowledge Team)
Summary of Lesson
Idea/Lesson Title
Use of elevated PAH (Tar) planings in HBM road foundation
Please rate your idea/lesson using the selectivity criteria and place a tick in the relevant boxes
** Refer to Selectivity Criteria on attached Sheet
below each criteria to indicate the impact it has.
Selectivity Criteria
Cost for
Project
JTR*
H&S** Reputation Sust/Env***
Rating
Time
* JTR = Journey Time Reliability
Highly beneficial
** H&S = Health & Safety
Medium beneficial
*** Sust/Env = Sustainability/Environment
Low beneficial
Neutral/no impact
Adverse Impact
Commercial Sensitivity - Please indicate if the idea has commercial sensitivity and therefore does not merit wider visibility,
No
by stating yes/no in the adjacent box.
Scheme
A46 Newark to Widmerpool Improvements
Approx works value (£m)
£260m
Richard Jones/Alistair Powell - 01949822300
Evidence Coordinator Name & Details
21/04/2011
Date Submitted
Key Issue:
The safe re-use of Coal Tar road planings within the site to avoid disposal off site as hazardous waste.
Short Overview of Issue
During site investigations, areas of the existing A46 carriageway were found to contain PAHs. Rather than dispose of this
material off site, which is hazardous waste attracting a high landfill tax, we developed a methodology to test, classify and
re-use in the permanent works in bound and unbound materials.by testing, grading and designating stockpiles with varying
levels of PAH for use in sub-base (57,000t) or HBM material (11,000t).
Solutions to the Problem or Opportunity
URS Scott Wilson were commissioned to evaluate the site investigation data, produce a report outlining the procedures for
on site testing, classification of the affected planings and for their Qualified Person under the Definition of Waste:
Development Industry Code of Practice to approve the management procedures to be employed. This negates the need
for formal approval by the Environment Agency. The attached flowchart shows the methodology and decision process.
The site UKAS accredited laboratory undertake UVF testing, (normally a specialist analytical chemistry lab test) on site to
give same day results, enabling rapid decisions to be made on the destination and treatment of the planings.
Risk of misclassification or operational error leading to the the wrong material being placed in unbound areas. Mitigated
by increased site testing and rigorous quality control.
Associated Risks & Issues:
Departures required
None - Covered under the Definition of Waste: Development Industry Code of Practice, September 2008. Also, EA
Regulatory position statement MWRP RPS 075, Version 1, December 2010.
Justification of Selectivity Matrix Indicators
Cost, Sustainability and Environment: Reduced raw material and therefore reduced cost and more sustainable.
Reduced transport and landfill (Hazardouse Waste) costs and less CO2 emissions. Maintain our commitment to zero
waste to landfill. Solution developed with the EA agreement.
Time: As long as testing and designation can be done ahead of installation there should be no effect on programme. The
reduced haulage distances aid programme and resource constraints.
JTR: Reduced off site road movements therefore contributing to improved JTR.
H&S: Reduced road miles decreases the risk of incidents between site traffic and public. Proven leachate results for long te
HA Reputation: Reduced cost, zero waste to landfill, more sustainable solution.
Repeatability - Please provide your assessment This method of classification and designation can be applied to other projects where PAH's are present in existing road
construction and there is a requirement to remove all or part of the road construction.
on whether the idea is a one off for your
scheme or if there is potential for wider cost
benefits if used on successive projects.
Does this idea have links to any other ideas
already on the Ideas Knowledge Bank
Database or the HA Toolkits?
Yes - L24 - Tar planings used as an aggregate in concrete
Please provide any supporting evidence
pictures, graphs, figures, documents or other
evidence.
Material Characterisation flowchart
Verification Group Decision
The VG liked this idea as anything that re-uses waste that is toxic is good for
sustainability. The Environment Agency has changed its requirements so Tar Planing is
not categorised as toxic. It is understood that this idea was used on the M25
Homesdale Tunnel and saved £3M. Ideas to be placed on KB.
Please forward a copy of this completed pro-forma to the HA Project Manager for information
Version 5 - 24/02/11
Comments from Richard Jones about Cost Benefits for Idea L90 Use of
Elevated PAH (Tar) Planning
The work has yet to be completed but we currently expect to re-use in
the works 68,000 tonnes of tar planings. Disposal off site would cost of
the order of £180/T (Landfill tax is about 60/T, then there is tip costs
and haulage). So this is a very significant sum However this should not
be seen as a cost saving.
Dealing with Coal Tar materials was a risk item for the project and we
have used innovative testing and classification to mitigate the risk.
Happy to explain this to the Verification Group via a telecon if you
wish.