A former market garden area is proposed for residential redevelopment. 
Consultants have been appointed by the owner to investigate any impacts from the  former site usage.  A voluntary audit is being undertaken of the work.

A stage 1 Preliminary Site Investigation (PSI) has identified the following potential impacts:

• Former Market Garden areas, used for vegetables, crops and grapes, which  may have had organo-chlorine/phosphate (OCP) and herbicide/insecticides and fertiliser applications
• Mechanical workshops: use of Paris Green wood preservatives, fuels, oils, degreasers.
• Sheds used for paint storage.
• Former poultry operation: nutrients, formaldehyde (disinfectant)
• On-site fill and waste disposal
• Run-off to soak wells and sumps
• Abandoned vehicles
• Potential use of asbestos in fencing and roofs of on-site buildings.

A detailed Sampling and Analysis Plan (SAP) will by the Consultant in cooperation with the auditor to guide a stage 2 Detailed Site Investigation (DSI) to identify any impacts from these sources.    
Stuart Jeffries
Hydrosolutions Pty Ltd

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(Audit 17)

MNA (also “intrinsic or passive” remediation) may be defined as naturally occurring physical/ chemical/ biological process/es that reduce concentration & mass of polluting substances in groundwater (DEC, 2004) and soil.  MNA is a process of field monitoring & laboratory analysis to confirm that the remediation is occurring as expected.  MNA processes can include:
• Biodegradation (consumption by microbes & conversion into less/ non-harmful substances)
• Physical processes (e.g. adsorption (soil adherence), evaporation etc)
• Chemical processes (e.g. hydrolysis, precipitation, cation exchange, oxidation/ reduction, aerobic/ anaerobic degradation, fermentation/ reductive dechlorination/  dehydrohalogenation)
• Dilution (mixing with unpolluted water)- non-destructive!.

However, MNA must:
• Demonstrate a reduction in mass/ concentration/ toxicity occurs.
• Be sufficiently rapid to prevent impact on receptors & minimise plume expansion
• Achieve remedial goals within one generation, ~30 years.
• Include monitoring over 2-3 years+ that MNA is occurring
• A contingency plan if MNA is not achieving remedial goals.

Typically MNA is part of a remedial strategy which includes removal of the source (e.g. leaking tanks/ PSH on the water table) & may be used with other active strategies (e.g. air sparging/ vacuum extraction/ oxidation agents etc)       
 

A Four Stage Process (WA DEC):

1) Screening Stage (Assess Viability)
• A soil & groundwater investigation establishing contaminant source, extent/ nature of the plume, aquifer characteristics & groundwater geochemistry
• Identification of sensitive gw receptors
• A feasibility assessment of MNA for the identified site characteristics, (e.g. Low to High)

2) Demonstration Stage (quantitative demonstration of the rate of MNA)
• (Primary evidence): historical monitoring data of concentration decreases with time/ distance
• (Secondary): geochemical mass balance assessment and/or observed data for a shrinking or stable plume.
• (Tertiary): Laboratory demonstration of degradation processes. 
This may require additional site investigation work.

3) Assessment Stage (Is MNA an acceptable remedial option?)
• Identify receptors to be protected, remedial targets to be achieved, & a remedial timescale)
• Modelling of the MNA process/es & aquifer environment, including predictive scenarios
• Reporting of the assessment results to DEC

Following acceptance of MNA as a suitable remedial option:

4) Implementation 
• Design of a monitoring program (Sampling & Analysis Plan)
• Monitoring reports submitted to DEC
• Recommendations whether remedial goals are achieved, or on-going monitoring is required.

Adopted from DoE 2004 (Use of MNA for Gw Remediation)
 
Advantages & Disadvantages:

Advantages:
• Transformation into innocuous by-products (e.g. CO2, ethene, H2O)
• Relatively non-intrusive, allowing ongoing use of infrastructure
• Uses natural process/es
• No waste production
• Lower energy use/ emissions

Disadvantages:
• Longer time-frames to remediate
• Longer monitoring periods
• Complex site characterisation
• Affected by environmental changes (e.g. renewed mobility)
• Secondary toxicity (of transformed chemicals, e.g. TCE>VC)
 

Typical Applications:
• Hydrocarbon contaminated sites (e.g. service stations/ underground storage tanks/ fuel farms, for TRH, BTEX, PAHs)- Chlorinated hydrocarbons (e.g. solvents)
• Landfill leachate impacts (e.g. NVOCs, NH4, Cl, phenols, OCs, PAHs etc)
• Non-point sources (e.g. OCPs)

Useful References:
www.claire.co.uk (SIReN)
www.sandia.gov/eesector/gs/gc/na/mnahome.html (US government MNA Toolbox)

Stuart Jeffries
HydroSolutions Pty Ltd

Western Australia’s leading independent team with a proven track record in groundwater/ hydrogeology, surface water/ hydrology, auditing, contaminated land management and development projects.  We combine reliable expertise with regulatory knowledge, delivering high quality output and performance on time and budget.  We welcome technically challenging projects from commercial & government clients

Groundwater Resource Exploration
• Desk appraisal
• 26D Exploration Licenses
• Geophysical exploration
• Design/ supervision of drilling programs
• Test pumping (AS2368)
• Monitoring programs

Potable and Process Water Supply
• Potable water analysis and interpretation
• Source protection assessments
• Multiple barrier (ADWG 2004)
• Monitoring program design and implementation
• Sustainable yield assessment

Borefield Construction and Development
• Design/ supervision of bore construction
• Hydraulic testing
• Pump/ riser selection and installation
• Wellhead design
• Pipeline design and construction

Dewatering
• Design of dewatering programs
• Implementation and management
• environmental factors/ beneficial uses/  impacts
• Modelling assessments
• Subsidence assessments
• Water inflow/ disposal/ reuse/ reinjection

Numerical Modelling
• Regional/ catchment/ local
• Borefield interference
• Radius of influence
• Dewatering assessments/ design
• Groundwater/ surface water interaction

Surface Water/ Hydrology:
• Open pit evaporation
• Modelling
• Rainfall/ Run-off/ Infiltration
• Water balance Contamination
• Site investigation
• Hydrochemical sampling/ analysis/ interpretation
• Solute transport modelling
• Risk assessment
• Design & implementation of contaminant recovery programs

Hydrogeological Reports
• Groundwater well licensing (Form A, 5C license to take groundwater)
• (SWP19) Hydrogeological assessments, H1, H2 and H3 level
• Preparation of operating strategies
• Borefield Monitoring Reviews (BMRs)
• Operating license compliance

Aquifer Storage and Recovery/ Managed Aquifer Recharge (ASR/ MAR)
• Initial appraisal
• Numerical Modelling
• Hydrochemical modelling (phreeqe/ netpath)
• Water treatment
• System design and implementation

Tailings Dams
• Design of monitoring programs
• Seepage appraisal
• Groundwater quality impact
• Reporting

Acid Rock Drainage (ARD)
• Investigation
• Acid/ base accounting
• Management planning
• Cover design
• Neutralisation
• Dewatering management plans

Geology/ GIS:
• Interpretation
• Geophysics

Stuart Jeffries
Hydrosolutions Pty Ltd

Western Australia’s leading independent team with a proven track record in surface water/ hydrology, groundwater/ hydrogeology, auditing, contaminated land management and development projects.  We combine reliable expertise with regulatory knowledge, delivering high quality output and performance on time and budget.  We welcome technically challenging projects from commercial & government clients

Surface Water/ Hydrology:

• Crop water/ irrigation requirements
• Drainage systems
• Groundwater/ surface water interactions
• Infiltration/ recharge estimates
• Mine site water management
• Monitoring program design & implementation
• Nutrient & Irrigation Management Plans (NIMPs):
o Land-use (Runoff/ infiltration factors, Soil properties/ Landforms)
o Water resources (surface/ groundwater)
o Land Management
o Nutrient application
o Drainage controls
o Protection of surface water/ groundwater
o Site monitoring & reporting
o Contingency planning
• Open pit/ water/ dam evaporative loss
• Rainfall/runoff & Infiltration factors
• Salinity studies
• Surface water/runoff quality
• Urban Water Management Plans (UWMPs):
o Small/priority catchments/ large scale
o Planning approval/ design/ objectives
o Site characteristics (Land use/ soil type/ properties/ Surface water flow/ Groundwater flow/ levels/ Contamination/ Acid Sulfate Soils/ Water Sustainability (Water balance/ Conservation (alternative water sources/ xeriscaping/ AAMGL/ Water use efficiency
o Stormwater/ Surface Water Management (Surface water (numerical) modelling/ Flood protection (1in100 year ARI) level/ Frequent Rainfall Events (1in5 (to 1in1) year ARI rainfall)/ Retention mechanisms
o Groundwater: (Groundwater (numerical) modelling/ AAMGLs/ Wetlands/ Groundwater Dependent Ecosystems (GDEs)/ Controlled gw level/drainage/ Bioretention/ riparian controls)
o Subdivision management: (Dewatering management plans/ Acid Sulfate Soils)
o Monitoring programs (design/ implementation)
• Water Balance: (Rainfall run-off/ Evapotranspiration loss/ Groundwater inflows/ outflows/ Storage change)
 
Acid Sulfate Soils (ASS):

• Dewatering Management Plans
• (ASS) Management Plans (ASSMP)
• Investigation/ assessment
• Treatment options (soil/ surface water/ groundwater)
• Reporting
Groundwater/ Hydrogeology:

• Acid Rock Drainage (ARD)/ Acid sulfate soils (ASS)
• Aquifer Storage and Recovery/ Managed Aquifer Recharge (ASR/ MAR):
• Average Annual Maximum/Minimum Groundwater levels (AAMGLs)
• Dewatering investigation/ modelling/ implementation
• Exploration/ Investigation
• Groundwater Dependent Ecosystems (GDEs)
• Hydrochemical Analysis
• Feasibility studies: Mining/ Industrial/ residential
• Monitoring Programs
• Numerical Modelling studies
• Surface water/ groundwater interactions
• Tailings Dams
• Reporting
• Resource Evaluation
Also:

• Contaminated Site Audits
• Contaminated Land
• Geology\GIS
• Site Remediation

Stuart Jeffries

Hydrosolutions Pty Ltd

Western Australia’s leading independent team with a proven track record in groundwater/ hydrogeology, surface water/ hydrology, auditing, contaminated land management and development projects.  We combine reliable expertise with regulatory knowledge, delivering high quality output and performance on time and budget.  We welcome technically challenging projects from commercial & government clients.

Groundwater/ Hydrogeology:

• Acid Rock Drainage (ARD)
• Aquifer Storage and Recovery (ASR)
• Average Annual Maximum/ Minimum Groundwater Levels (AAMGL)
• Beneficial uses/ environmental values
• Conceptual modelling
• Contamination assessments
• Dewatering design/ implementation
• Ecological Risk Assessment
• Equipment installation
• Exploration:
o Evaluation/ permitting
o Investigation
o Test pumping
• Feasibility studies: Mining/ Industrial/ residential
• Groundwater Dependent Ecosystems (GDEs)
• Hydrochemical Analysis
• Isotopic analysis/ dating
• Landfill investigation
• Licensing
• Managed Aquifer Recharge (MAR)
• Modelling:
o Numerical
o Analytical
o Water Balance
• Monitoring program design/ implementation
• Potable/ Process water supplies
• Reporting:
o Borefield Monitoring Reviews (BMRs)
o Notice of Intents (NOIs)
o H1-3 Assessments
• Recharge estimation
• Remediation:
o Investigation
o Design
o Implementation
• Resource Evaluation & Development
• Source Protection Plans
• Supervision/ management of drilling programs
• Surface water/ groundwater interaction 
• Sustainable yield assessment
• Tailings Dams
• Test pumping (AS2368)
• Treatment studies
• Water Balance studies
• Wetland studies
Geology\GIS:

• Database implementation
• Geographical Information Systems
• Geophysics
• Interpretation
• Soil properties
Surface Water/ Hydrology:

• Catchment studies
• Monitoring program design & implementation
• Modelling
• Nutrient & Irrigation Management Plans (NIMPs)
• Open pit/ water/ dam evaporative loss
• Rainfall/ runoff/ infiltration
• Salinity studies
• Surface water/ groundwater interaction
• Urban Water Management Plans (UWMP)
• Water Balance
Also:
• Contaminated Land
• Environmental (& Contaminated Site) Audits
• Risk Assessment
• Site Remediation

Stuart Jeffries

Hydrosolutions Pty Ltd

Western Australia’s leading independent team with a proven track record in groundwater/ hydrogeology, surface water/ hydrology, auditing, contaminated land management and development projects.  We combine reliable expertise with regulatory knowledge, delivering high quality output and performance on time and budget.  We welcome technically challenging projects from commercial & government clients

Groundwater/ Hydrogeology:
• Acid Rock Drainage (ARD)
• Aquifer Storage and Recovery/ Managed Aquifer Recharge (ASR/ MAR):
• AAMGL
• Dewatering design/ implementation
• Exploration/ Investigation/ test pumping
• Hydrochemical Analysis
• Feasibility studies: Mining/ Industrial/ residential
• Modelling (numerical/ analytical)
• Monitoring program design/ implementation
• Reporting/ NOIs/ H1-3/ Licensing
• Resource Evaluation & Development
• Supervision/ management of drilling programs
• Tailings Dams
Surface Water/ Hydrology:
• Catchment studies
• Monitoring program design & implementation
• Numerical modelling
• Nutrient & Irrigation Management Plans (NIMPs)
• Open pit/ water/ dam evaporative loss
• Rainfall/ runoff/ infiltration
• Salinity studies
• Surface water/ groundwater interaction
• Urban Water Management Plans
• Water Balance
Contaminated Land:
• Acid sulfate soils (ASS)
• Contaminated Site Audits
• Health & Safety Plans: WorkSafe
• Industrial redevelopment/ effluent & waste management
• Investigation
• Landfill investigation & management:
• Monitored Natural Attenuation
• Monitoring
• Remediation
• Risk Assessment 
Environmental (& Contaminated Site) Audits:
• Contaminated Site Audits: (WA Accredited CS Auditor)
• Legislative compliance
• Pre-acquisition
• Due-diligence
• Regulatory compliance
• Liability assessments
• Consultative/Public Environmental Reviews (CERs/ PERs)
• Environmental Impact Assessments (EIAs)
• Works approvals
• Notice of Intent (NOIs)
Site Remediation:
• Industrial: Waste & Effluent Management
• Minesite: Tailings Dams/ Effluent Management
• Residential: Redevelopment of Brownfields
• Site Management Plans (SMPs)
• Remedial Action Plans (RAPs)
• Occupational Health & Safety Plans: WorkSafe
• Project Management & Implementation:
• Groundwater: Active/passive
Risk Assessment:
• Qualitative
• Quantitative
• Human Heath (HHRA)
• Ecological (ERA)
• Monitored Natural Attenuation
Geology\GIS:
• Interpretation
• Geophysics
• Database implementation
• Geographical Information Systems

Stuart Jeffries
Hydrosolutions Pty Ltd

Appraisal of contamination issues, chlor-alkali and organo chlorine manufacturing site, United Kingdom.

An assessment of groundwater contamination and environmental sensitivity issues was undertaken at the company’s Merseyside Operations. 

The site is the largest chlor-alkali and organo-chlorine (OC) chemical manufacturing site in the UK.

Chemical manufacturing commenced in the 1840’s, and has included saponification, chlor-alkalis, caustic soda, bleach,copper, hydrochloric and sulfuric acids, OC solvents,and more recently chloro-fluorocarbons (CFCs).  Other contaminants may also be present as by-products or catalysts used in chemical production processes or waste products. 

Soil, surface water and groundwater impacts have resulted from the historical operations.

The study reviewed the sensitivity of the hydrogeological setting, and identified potential contaminant migration routes to impact regional groundwater quality, surface water quality in the adjacent Weston Canal, and potentially marine water quality.

Recommendations were made for a comprehensive site investigation program based on common chemical manufacturing areas and likely contaminant sources.

Stuart Jeffries
Hydrosolutions Pty Ltd

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Contam10

A stormwater run-off model was developed for the Nelson Point iron ore handling & port facilities, to model sediment and potential contaminant loadings from the site into the Port Hedland harbour area.

Drainage catchments identified by BHPB were overlain by site geology and cut/fill plans to allow run-off coefficients to be allocated, using Geographical Information System (GIS) software.   

Evaporative loss was modelled based on published pan Et figures occuring during the storm duration.

Intensity-frequency-duration (IFD) run-off events were also modelled.

The model was calibrated against observed flow data recorded during historic storm events.

A similar run-off model was also developed for the Finucane Island ore handling facility.
Run-off catchments were defined from high-resolution aerial photography and a 0.5m digital elevation model.  Catchments & discharge points were verified by ground-truthing.

Sediment and contaminant loadings from individual catchments flowing to specific discharge points can be estimated from current and historic rainfall/ intensity events.

Stuart Jeffries
Hydrosolutions Pty Ltd

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Click here to send us details of your requirements
Click here for other example GIS projects

GIS3

A former residential estate in Queens Park, Cannington, is being redeveloped for ongoing residential use.  Consultants have been appointed to undertake investigation of impacts arising from the former
residential development and it’s subsequent demolition.  A Contaminated Site Audit (CSA) is being undertaken on behalf of the site owner, to support an application for rezoning at a higher residential density.
 
The former residences have been demolished.  Site impacts have been identified including:

• organo-chlorine/phosphate (OCP) herbicides in soils beneath the former footings
• potential metals, hydrocarbons and nutrients in former septic systems, and
• asbestos in/on soils from the removal of fencing. 

The area will developed in three stages. An initial trial area has been remediated and is currently undergoing additional validation works.  Two further stages are currently being investigated, including soil
and potential groundwater impacts. 

A Site Management Plan (SMP) is in development for the remaining stages.  

A voluntary Site Audit Report (SAR) will be prepared for each stage to accompany consultant reports and to provide recommendations for appropriate site classification to the Department of  Environment and Conservation (DEC).

Stuart Jeffries
Hydrosolutions Pty Ltd

Click here to see a project summary
Click here for details of our capabilities in Environmental Auditing
Click here to send us details of your requirements
Click here for other example Environmental Audit projects

(Audit 16)

A former residential estate in Queens Park, Cannington, is being redeveloped for ongoing residential use.  Consultants have been appointed to undertake investigation of impacts arising from the former residential development and it’s subsequent demolition.  A Contaminated Site Audit (CSA) is being undertaken on
behalf of the site owner, to support an application for rezoning at a higher residential density.
 
The former residences, which incorporated asbestos containing material (ACM) have been demolished.  Site impacts have been identified including organo-chlorine/ phosphate (OCP) herbicides in soils
beneath the former footings, potential metals, hydrocarbons and nutrients in former septic systems, and asbestos in/on soils from the removal of fencing. 

The area will developed in four stages:

• An initial trial area has been remediated and is currently undergoing additional
  validation works. 
• Three further stages are currently being investigated, including soil
  and potential groundwater impacts.

A Site Management Plan (SMP) is in development for the remaining stages.  

A voluntary Site Audit Report (SAR) will be prepared for each stage to accompany consultant reports and to provide recommendations for appropriate site classification to the Department of Environment and Conservation (DEC).

Stuart Jeffries
Hydrosolutions Pty Ltd

Click here to see a project summary
Click here for details of our capabilities in Environmental Auditing
Click here to send us details of your requirements
Click here for other example Environmental Audit projects

(Audit 16)