Building On Contaminated Land:The New Regime

Building On Contaminated Land:The New RegimeOverview of Presentation Given at IStructE HQ Wednesday 9th October 2002 by the IStructE & Parkman Environment

Christopher Evans JACOBS Infrastructure

SUMMARYSUMMARY

• Introduction

• Site Assessments

• Risk Assessments

• Remediation Options

• Conclusions and Recommendations

• Discussion

• Desk Study Example (Not included in presentation)

INTRODUCTIONINTRODUCTION

• Why is contaminated land such a big issue?

• Environment Agency figures put the estimated number of contaminated sites in England and Wales at 300,000 ha, OR equivalent area to Greater London!!!

• 57% of current and proposed housing developments will built be on ‘Brownfield’ sites due to the high cost and low availability of ‘Greenfield’ sites (commercial and industrial redevelopment much higher)

• Potential for 710,000 dwellings on ‘Brownfield’ sites (9 years supply at 50:50 split ‘Brownfield’ to ‘Greenfield’

• What is regarded as ‘Greenfield’ post BSE, Foot and Mouth, GM crops???

IntroductionIntroduction

• Why is this of significance to us?

• Civil and structural engineers are increasingly employed as Project Managers. The exposure to risks, both professionally and financially are increasing, but if handled correctly, it is a prime opportunity to show professional, practical and economic solutions and gain a foothold in the marketplace!

IntroductionIntroduction

• THE THREATS!

• Dabbling! If if doubt ask!!! Better still, transfer risk onto a ‘third party’ who are better able to assess, quantify and mitigate or remove the risks, e.g. Water and Environmental Division (transfer the risk but maximize profits)

• Thinking conceptually, not prescriptively. There are strict guidelines which should be adhered to. The statutory bodies such as EA, DEFRA, Water Authorities don’t take kindly to people thinking ‘outside the box’

• Lack of awareness of legal and financial liabilities, at best bad press, at worst, litigation and fines!

• Bad luck or bad judgement…….disturbing contamination and opening new pathways affecting new receptors!

e.g. Underpinning, Vibro compaction, Bored piles?

IntroductionIntroduction

• THE BENEFITS

• Reducing risk to JacobsGIBB, by reducing the likelihood of legal proceedings, fines, liquidated damages through either direct or inferred liability

• Maximize profits by utilizing ‘in-house’ specialists, exposing established clients to the wider family of Jacobs’ divisions and promoting our strength in depth.

• Enhanced client awareness and enhanced trust., increased cost effectiveness, and above all repeat work!

• Promotion of and establishment of Jacobs as number one player in the field of contaminated land, water and air

DEFINITIONS & CAUSES OF CONTAMINATED LANDDEFINITIONS & CAUSES OF CONTAMINATED LAND

• Definitions of ‘Contaminated Land’“Land that contains substances which, when in sufficient quantities or concentrations, are likely to cause harm, directly or indirectly, to man, the environment or on occasion to other targets”

NATO / CCMS (1985)

OR RATHER;“Contaminated land is any land which appears to the local authority in whose area it is situated to be in such a condition, by reason of substances in, on or under the land that a) significant harm is caused or there is a significant possibility of such harm being caused(Environmental Health, Health and Safety Executive)b) pollution of controlled waters in being, or is likely to be caused……”(Environment Agency)ENVIRONMENT ACT – England & Wales 1995

Significant HarmSignificant Harm

• What is meant by ‘significant harm’Human Health – death, serious injury (immediate, e.g. poisoning, long term, e.g.

chemical, biological, radiation exposure, risk to wider public through ingestion into food chain, water supply etc, deterioration in air qualityEnvironment – Ecosystem protected by legislation, e.g. SSSI, nature reserves, protected species, controlled waterwaysProperty – Buildings, livestock etc.

• What is meant by ‘controlled waters’ Inland surface water, ground water, coastal margins – hydraulic continuity

Definition:“Entry in controlled waters of any poisonous, noxious or polluting matter or any solid waste matter”

Causes of contaminationCauses of contamination

• Human activityPast use of the site, industrial processes, leaks, spills, dumping?Filled ground, importing contamination from elsewhere

• Naturally occurring contaminationHeavy metals of geological originMethane gases from peat and coal seams, landfill sitesRadon gasAfter recent BSE and Foot and Mouth outbreaks, decomposing animal remains?

The Legislative FrameworkThe Legislative Framework• Legal constraints to prevent new contamination

Waste Management Licensing (WML) – Landfill controls etc, imposition of taxation dependant on level and type of contamination, costs for off-site removal of contaminated material is set to increase Integrated Pollution Control (IPC) – Taxation of ‘polluted / contaminated’ land by the offenderremediate existing contamination “Suitable for Use” – To remediate the contamination at source to a level suitable for its intended use only, possible government assistance with regards to grants, tax breaks etcChange of use – Planning Control application (See guidance below)Current Use – Environment Act Part 2A covers those areas of development not covered by Planning Process

• Change of usePlanning Policy Guidance (PPG) 23 – Planning and Pollution ControlBuilding Regulation C2 – Contamination in constructionsEnvironmental Health – Local Authority controls to protect people Environment Agency – Effectively all water and land issues within England and Wales (beware of inconsistencies and bureaucracy!) Scottish Environment Protection Agency & Department of Environment for Northern Ireland

The Legislative FrameworkThe Legislative Framework• Current use

The new regime came into force in England on 1st April 2000, with Part 2A of the Environment Protection Act 1990 being inserted into the Act, by Section 57 of the Environment Act 1995 (essentially Part 2A IS Section 57, and both notations are used so be aware). Part 2A has now been incorporated by both the Scottish and Welsh assemblies into the legislative framework

The new regime affects all land and property owners

It is in the process of being implemented by all Local Authorities and the Environment Agency, who are inspecting and identifying sites of contamination for future litigation

Environmental LiabilityEnvironmental Liability• Who is liable under the act?

As previously mentioned all land and water ‘owners’

Regulations identify liability – i.e. those who cause or knowingly permit the contamination to take place – N.B. liability can be apportioned to professional advisors – Jacobs!!!

Voluntary remediation is suggested and if none is forthcoming, then a formal notice for remediation can be issued after 3 months has elapsed, after this the remediation is enforceable by law, and the offender(s) are placed on a public register, not very good publicity for consultants!

SITE ASSESMENTSSITE ASSESMENTS

• The usual methods of a ‘site assessment’ may include the following;

Desk studyHistorical records, maps, mining records etcGeological mapsHydrogeology

Site reconnaissanceIntrusive investigation

Trial pitsBoreholesStandpipes

• The new assessment approach must be undertaken with these in mind but also in the context of;

SOURCE > PATHWAY > RECEPTOR as a linked and changing relationship

Site AssessmentsSite Assessments

• Contamination must not be thought of as a static, but DYNAMIC PROCESS which can alter with time, climate, site conditions and above all when disturbed

THE ASSESMENT MUST TAKE THIS PRINCIPLE INTO ACCOUNT

• How should you asses a site?Understand the sourcesIdentify the receptors (humans, animals, plants, air and water)Sketch the conceptual model with all the SOURCE > PATHWAY > RECEPTORS

Identify the ‘zones’ and ‘averaging areas’

Understanding the sourcesUnderstanding the sources

• Human activity• Naturally occurring contamination• Transfer

Contamination can partition into different physical states:Solids (absorbed)Solution (dissolved)Vapour / gasesSeparated phase (NAPLs)

• Fate

BiodegradationPersistence (half life of radioactivity)

• TransportMobilityMigration

Understanding the receptorsUnderstanding the receptors

• How sensitive is the site?Residential with gardensResidential without gardensAllotmentsParks, playing fields and open spaces for recreationCommercial and industrial

• Receptor = Human HealthIngestion of soilIngestion of contaminated foodDermal contact with soil

Respiratory contact with dustRespiratory contact with vapours / gasesCombustion and explosion (methane)

Understanding the receptorsUnderstanding the receptors

• Receptor = EnvironmentGroundwater qualitySurface water qualitySoil quality – ecosystem (flora and fauna) - food chain – man!

• Receptor = Material durabilityBuried foundations (sulphate, acidic soils)Services (UPVc pipe, clay pipes)Will the contamination lead to problems above DPC level, e.g. methane – explosion

risk in confined areas, designable risk?

RISK ASSESMENTRISK ASSESMENT

• How do we decide if a site is contaminated?????Statutory documents - PPG 23

- EA Part 2A- Building Regulations C2 and Approved Documents- NHBC Standards Chapter 4:1 – Land Quality and Housing

Guidance

• Materials testing for those liable to cause harm to flora or fauna;17 substances including;

arsenic (though naturally occurring in some soils)cadmiumleadmercurycopper, zinc, nickel

‘organics’

Risk AssessmentRisk Assessment

• What next?Apply ‘trigger’ values for soil; e.g cadmium - 3 mg/kg for gardens

- 15 mg/kg for open spaces

• Simple concept of ‘threshold’ and ‘action’ values then applied;

Below ‘threshold’ = No actionAbove ‘action’ = Remediate to below ‘threshold’In between = Use judgement (tricky and requires skilful and

often protracted consultation with EHO or EA)

• What is the problem then – job done?

No!

Risk AssessmentRisk Assessment• The ‘old method; is flawed and outdated. • It needs updating – House of Commons select committee findings (1990)

called for more scientific and prescriptive based techniques to account for advances in technology

• For example copper and zinc, though phytotoxic (to plants), large exposure or large doses required to be ingested by humans, therefore not specifically needed when considering human activity

• ‘Generic’ assessment of a site from a limited statistical base, i.e. a few trial pits and scattered boreholes, not indicative of whole site, therefore may be over conservative

• Poly aromatic hydrocarbons (PAH) values are too high by an order of magnitude

• Subjective interpretation between ‘threshold’ and ‘action’, leading to non conformity across EA and EHO rulings

• Not all contaminants have action values, as many are naturally occurring to varying degrees

• Limitation on specific values for each contaminant for otherwise ‘clean site’

Risk AssessmentRisk Assessment

• What has been done to help?Planning Guidance and Environment Act – Prescriptive design approach to reduce confrontation and division

Guidance documents – NHBC 4:1 etc – Descriptive guidance

Best Practice Guides – Helping to standardise and unify methods

• Soil analysis; Soil Guideline Values (derived using DETR software and CLEA modelsSite specific risk assessments by specialists

• CLEA Model – ‘A probabilistic model for quantifying risk to human health from contaminated land

C (Contaminated) L (Land) E (Exposure) A (Assessment)

N.B Jacobs Infrastructure have experts in the use of CLEA models, notably Menfang Chen and Jane Thrasher within Water and Environmental Division – so use their expertise to the full!

REMEDIATION OPTIONSREMEDIATION OPTIONS

• Remedial strategySpecify, and agree with statutory bodies concerned, acceptable levels of risk reductionIdentify the remedial strategy so that its meets its objectiveDesign and implement the strategyValidate the strategy upon completion to ensure it has met all the requirements set of it

Consider each element of the;SOURCE > PATHWAY > RECEPTOR principle

• Dealing with the sourceThermal treatment Physical treatmentChemical treatmentBiological treatmentStabilisation and solidification

Remediation StrategiesRemediation Strategies

• Ex-situ disposal - Off-site treatment following excavation or extraction

• In-situ disposal – On site treatment prior to removal from ground

• Problems associated with Ex-situ disposalMaterial is classified as waste if it is surplus to the requirements, to either the owner or the holder of the waste

(Subjective view – waste may be ‘clean earth’ which can be used for re-grading or making up ground profiles)

• What is waste?Controlled waste; Household, commercial, industrial, and such subject to regulation.

Non-controlled waste; Agricultural, mining and quarry waste

Remediation StrategiesRemediation Strategies

• Controlled Waste;

• Inert; Non-biodegradable; No physical or chemical changes over time

Non-hazardous; Do not contain significant harmful or toxic materials

Hazardous (special); Significant toxic or highly mobile contaminants

• Options;

On site disposal = Need a licence or exemption certificate

Off site disposal = Pay landfill tax

Remediation StrategiesRemediation Strategies

• On site waste disposal

It is a criminal offence to deposit, treat, keep or dispose of controlled waste without a WMLWML can only be obtained from EA

The WML can be surrendered at any time if requested by the EA

Liabilities = ‘Blight’ and unlikely to be re-instated

• ‘The exclusions

Minor regarding re-grading operationsIf < 1000m3 the EA will not enforce licenceIn ground barriers to prevent pollution leakagesTemporary storage facilities

Remediation StrategiesRemediation Strategies

• The ‘exemptions’Demonstrate incapable beneficial use without improvement to render it ‘suitable for

use’

If < 20,000m3 / ha (max 2m cap) Requires planning permission Ecological improvement Construction of roads and buildings

• On site disposalMinimize waste;Use potential ‘waste’ in a pre-planned mannerUse inert excavated soil for landscaping and noise bundsBe aware of WML Regulations – BLIGHT!Minimize the spoil from foundation excavations – ‘holistic approach’

Remediation StrategiesRemediation Strategies

• Mobile plant licensesApplication of process based remediationEquipment used to treat or dispose of the wasteSurrender test is waivedMust be portable

• Off site disposalLandfill tax;Standard rate - £13.00 / tonne (Will almost certainly increase, possibly to over £30 /

tonne)Lower rate – £2.00 / tonne (‘Inert’ material)Tax exemption only where the spoil is non construction

• Minimize wasteLeave old excavations in-situ if possibleUse shallow foundations where possibleAvoid over digRecycle where possible – crushed concreteAvoid earthworks in wet weather to reduce run off and leaching

Remediation StrategiesRemediation Strategies

• Example of off-site removal30 house site with 500mm clean coverClassified as ‘Special Waste’ by EHO and EARe-negotiation, using CLEA model and chemical analysis, as ‘Inert Waste’Original estimate = £1.5millionActual cost = £0.3millionCost saving £40,000 per houseCost saving to relationship - £PRICELESS!!

CONCLUSIONS AND RECCOMENDATIONSCONCLUSIONS AND RECCOMENDATIONS

• Civil and Structural engineers are increasingly becoming Project Managers and carrying the can for the successes or disasters of their projects, so ponder this carefully……

• Have you the relevant expertise to fully appreciate the risk to Jacobs? If not, use experts, DO NOT dabble!

• Make suitable allowances for a sufficiently ‘robust and thorough’ site investigation, and try to educate the client to ‘front load’ the project financing, better to pay a little now than a lot later!

• We are trying to develop relationships, gain industry supremacy and become the number one choice for our clients! We are selling OURSELVES and OUR COMPANY, not just our divisions! JacobsGIBB should succeeds together and fails together, let’s succeed together!

CASE STUDY EXERCISECASE STUDY EXERCISE

• The following is an idealised example of how a geo-environmental consultant may be of benefit / detriment to a project, and how they could save / cost time, money and face to the project manager who appointed them.

• It is not intended to be a prescriptive guide but only to illustrate where a project manager may use reasoned engineering judgement and expert advice to gain the best solution to a problem.

• The figures and numbers used are indicative and serve only to illustrate the costs and savings that could reasonably be expected with such an project? Is this model familiar, it probably will become so!