Daym ion Jenkins

Risk Based Developm ent , Mat er ials Managem ent , and Rem ed iat ion Technologies

November 2017

Context

Remediation - Precautionary Approach

4

Redevelopment Drives Vast Majority of Remediation • The Housing and Planning Act 2016 - Will kick-

starting a national crusade to get 1 million homes built by 2020

• Compels local authorities to keep a comprehensive register of brownfield sites suitable for housing

• Welsh Government estimates around 200,000 new homes by 2030

• PPW states The Welsh Government will seek to ensure that “previously developed land is used in preference to greenfield sites

Waste hierarchy – Article 4, Directive 2008/98/EC

Commercial Reality - Established Soil Treatment Centres

FCC/Provectus, Rowley

West Midlands

Dunton Environmental Wolverhampton

Biffa/Biogenie, Meece Stafford

Biffa/Biogenie, Westmill Hertford

Augean, Kings Cliffe Peterborough

Biffa/Biogenie, Skelton Grange

Leeds

Augean, Port Clarence Teesside

Biffa/Biogenie, Redhill Surrey

BATNEEC v CATNAP !

Neal Soils Cardiff

Constraints Based Development

Case Study - Master planning to reduce remediation requirementsto ensure viability

Materials Management

Material Management Plans

CL:AIRE Code of Practice for Material Management Plans Golden Rules: R euse any soils w ith in a d evelop m ent site as long as th ey are suitab le for use and d o not p ose a risk to th e environm ent, th erefore:

— Risk Assessm ent required N eed s to b e a req uirem ent to reuse R ead th e guid anc e. h ttp s://w w w .c la ire.c o.uk /p rojec ts-and -in itiatives/d ow -c op /28 -fram ew ork -and -guid anc e/111-d ow -c op -m ain-d oc um ent D oes not ap p ly in S c otland .

Materials Management Plan Example

• Cable Manufacturing and Engineering Works • Ground Investigation identified extensive

heavy metal, asbestos and hydrocarbon contamination Localised LNAPL and groundwater impact

• 50,000 m3 of contaminant impacted soil excavated, treated on-site using ex-situ bioremediation

• Re-profiled in suitable locations across the site • Robust Materials Management Plan and verification in line

with CL:AIRE protocols

Remediation Options Appraisal and Technology Selection

How it Works?

Define the Problem

Set the Objectives

Design the Process Deliver Gat her t he

evidence

Site Characterisat ion

& Risk Assessm ent

Due Diligence Rem ed iat ion St rategy

Pilot Stud ies &

Bench Tests

Diagnost ic Invest igat ions

Cost Benefit & Sustainab ilit y

Appraisal

(System ) Perform ance Monitoring

Verificat ion & Monitoring

Cont ract ing

Lines of Evidence

Monitoring

Rem ed iat ion Specificat ion

Detailed Design & Rem ed iat ion

Im p lem entat ion Plan

Resident Engineer

MMPs / AMPs

Opt ions Appraisal

A St ructured Approach

Large % of time spent “assessing risk”.

Large budget (& time) remediating sites.

But……Insufficient time designing and planning cost effective and/or successful remediation programme.

http://webarchive.nationalarchives.gov.uk/20140328160926/http://cdn.environment-agency.gov.uk/

Who does th is p iece?

Does th is happen?

Key Concepts

“Fai l Sm al l W in Big”

Gather Rem ediat ion Focussed Inform at ion

Pilot Stud ies Bench Tests

Targeted Invest igat ions

Key Concepts

“Design w it h t he End in

Mind ”

Easy to Write Difficult to Achieve

Hard to Write Easier to Achieve

Fixed standard based on conservat ive

assum pt ions

Lim ited Flexib ilit y

Pass risk & perform ance to

cont ractor

Ob ject ives considered against

cost & benefit

Flexib le end points based on sustainab le

effort and risk m it igat ion

More but sm arter data requirem ents –

lines of evidence

Better G

overnance, Und

erstanding of R

isk and

Increased Perform

ance

Increased chance of failure and dispute

Technology Selection

ht tps://frtr.gov/m atrix2/top_p age.h tm l

Choosing the Techniques - Remedial Options Appraisal

And most importantly…….

Define an Achievable End Point!

Remediation Monitoring, Validation and Natural Attenuation

Case Study Groun d w ater C on tam in an ts:

• V olatile organ ic c om p oun d s • P olyc yc lic A rom atic H yd roc arb on s • A lip h atic an d arom atic h yd roc arb on s • H eavy m etals

R em ed iation Targets: O n erous (c .0 5 .µ g/l for vin yl c h lorid e for exam p le) R em ed iation : R iver Terrac e D ep osits on ly Treatm en t : W in d ow Lim ited c . 6 m on th s H istoric R em ed iation Targets d evelop ed b y oth ers from c on servative

D Q R A !

Primary Considerations Considerat ion Feat ure Precludes

Geology/Hydrogeology

Granular, hom ogenous, th in – app licab le to m ost technologies

Very lit t le

Contam inants:

Treatab le though d ifferent m echanism s Inorganic

One technology to effect ively t reat all CoC. Inorganics lim ited

Tim efram e Lim ited for act ive t reatm ent (i.e. 6 m onth w indow for access)

Most p rocess based or at tenuat ion based technologies

Rem ediat ion Targets: Made from unobtain ium (e.g.0 .5.µg/l target for vinyl ch loride, no target for DCE. etc.)

Most technologies in availab le t im efram e

Possible Groundwater Technologies Technology Const rain t Yes/No Pum p and Treat A c c ess/D isrup tive

Targets n ot ac h ieve in tim efram e N o

In -situ b io-rem ed iation Too slow C onc entrations inh ib itive levels

N o

P erm eab le R eac tive B arrier D oes not treat sourc e Fin ite lifesp an

N o

Th erm al Treatm en t D iffic ult to C ontrol off-G as Length y E stab lish m ent/S etup

P ossib le?

A ir S p arge D iffic ult to C ontrol O ff-G as Length y E stab lish m ent/S etup A c c ess/D isrup tive

N o

In -situ C h em ic al R ed uc tion (e.g. Z V I)

S p eed of treatm ent D iffic ulty in ap p lying

P ossib le

In situ C h em ic al O xid ation S p eed of treatm ent (too fast) N atural O xid ant D em and

Yes

Approach • Realistic view of what can be achieved • Develop a hierarchy of treatment based on toxicology • Lab Trial to prove technology • Which technology?

In-situ Chemical Oxidation

• 110 Injection points 14km of buried delivery lines • Industrial scale oxidant processing plant mixing • 300 tonnes of potassium permanganate (over 2 injection rounds); • 100 tonnes of Fenton’s Reagent (over 2 rounds) • 15m3/hour of oxidant • Total volume of reagent injected = >60M litres • …….Injected over 60 calendar days (24/7)

Tetrachloroethene (PERC) Treatment

Naphthalene Treatment

Treatment Efficiency

Closing Note of Caution “As we know there are known knowns. These are things we know that we know. There are known unknowns. That is to say, there are things that we know we don't know. But there are also unknown unknowns. There are things we don't know we don't know…” Donald Rumsfeld daymion.jenkins@wsp.com 07887 059752