Posted: September 13th, 2017

ENVIRONMENTAL REMEDIATION

ENVIRONMENTAL REMEDIATION

Please refer to the Rules for Submission of Assignments in the course outline. These rules cover the requirements of referencing, late penalties, extension requests and a warning on plagiarism. Be sure not to plagiarise. Where web sites are accessed and material included, the web address and date of access must be appropriately referenced. Note that penalties for plagiarism are severe and may result in students being excluded from the course or their degree program.
A hard copy of the assignment must be lodged in the ENVS3007 assignment box in the Geology/Earth Sciences Building no later than the date/time specified above and a copy lodged electronically through Blackboard. Do not submit your assignment through the Student Hub.
An assignment cover sheet (see Blackboard) form MUST be completed and attached to the hard copy of the assignment, otherwise the assignment will not be marked. No assignments will be accepted by email and no requests for extension will be considered after the due date. Extensions will only be considered before the due date for documented reasons involving hardship or medical illness for which a request for Special Consideration has been made through the Student Hub. The assignment must be word-processed (including all calculations) and the Harvard method of referencing used.
The assignment is compulsory and is worth 20% of the course grade.
Question 1
In many urban locations where industries such as metal processing and smelting have been undertaken, there remains a legacy of heavy metal contamination of soils. This may be due to a variety of industrial activities including spillages, poor site management, dumping of wastes and atmospheric fallout of particulates. In situations where concentrations exceed established guidelines, there is concern because a number of the metal forms can be toxic and they can bioaccumulate in the environment.
Assume that at a former industrial site in NSW, the concentrations of heavy metals exceed established guidelines and therefore “regulation” is warranted by the EPA. On this basis the site has been declared Significantly Contaminated and a Remediation Order issued. Note that in this part of the assignment your answer should not exceed four (4) word-processed pages (not including references) and that the references used in this question need to follow this answer.
i. clearly outline the legislative responsibilities which would exist with respect to the remediation of this contaminated site.
2
ii. if investigations ascertain that the site is contaminated by heavy metals, outline the possible fate of three of the principal metal elements which may be present in the soil.
iii. provide a brief review of possible remediation and site cleanup technologies for each or all of the metal contaminants which may be appropriate to consider to address the Remediation Order on the site.
Question 2
Go to Blackboard and download the plan of an area adjacent to an estuary which shows the locations of three groundwater bores drilled by a consultant hydrogeologist (SK3491, SK3524 and SK3515). The bore (collar) levels relative to AHD and standing water levels (SWL) on 16 March 2009 are shown in the table below. The local Council is interested in the hydrogeological conditions with respect to a potential potable water supply for the local community and is concerned about the risk of contamination from a disused petrol station (the approximate location of the UST is marked with an x on the plan. While the facility operated for 10 years, there are no records as to whether the UST was ever removed from the site and there is concern that it may have been leaking for most of this time.
Bore levels relative to AHD (m) Bore No. Collar level relative to AHD (m) SWL from surface (m) 16-Mar-2009
SK3491
7.65 m
6.35
SK3524
1.47 m
2.35
SK3515
1.26 m
0.41
Part of one of the borelogs (SK3524) obtained from an earlier drilling program also needs to be downloaded from Blackboard. As well as this borelog information, the results of a chemical analysis of the water sample collected from this bore on the same day are provided in a table below. A pump test on the groundwater was not undertaken by the hydrogeologist and no assessment of saturated hydraulic conductivity has been made so far.
Water quality data obtained from sample collected from Bore SK3524
at 6 m AHD 16-Mar-2009
Note: saline water encountered at 16 m AHD Parameter (units) Concentration Parameter (units) Concentration
pH (units)
5.2
Sodium (mg/L)
53
EC (uS/cm)
927
TPH (mg/L)
Trace
Chloride (mg/L)
71
Bicarbonate (mg/L)
18
Calcium (mg/L)
56
Sulphate (mg/L
86
Magnesium (mg/L)
27
Iron (mg/L)
2.5
Nitrate (mg/L)
55
Turbidity (NTU)
50
Escherichia coli (orgs/100mL)
50
Dissolved Oxygen (mg/L)
3.5
3
Using the available information, answer the specific questions asked (using numbered section headings), and where you have undertaken calculations, clearly note any assumptions you have made and the basis for them,
i. determine the direction of groundwater flow based on the water level information provided and indicate this on the attached plan (measure distances from centre of bore). Calculate the hydraulic gradient of the groundwater and determine the average velocity of movement along this hydraulic gradient. Refer to the borelog information to justify any assumptions you make.
ii. indicate on the plan where a plume might be located (to scale) if subsequent investigations find that the tank has been leaking. Briefly discuss whether Council should be concerned with respect to its proximity to the estuary and the planned potable water supply from SK3524 if this is the case.
iii. review the water quality and borelog data provided and assess the likely aquifer quality with respect to its use as a potable water source. Also discuss where any further work hydrogeological investigations might be directed on your recommendation.
iv. if further investigations find that the groundwater is contaminated by total petroleum hydrocarbons (which exceed the established criteria), describe the compounds likely to be present in the groundwater and briefly outline a cost effective method which might be considered if the site is to be remediated.
References
Ahmad, I. & Pichtel, J. (2005) Heavy Metal Contamination of Soils: problems and remedies, Plymouth Science Publishers, Enfield NH.
Alloway, B.J.and Ayres, D.C. (1997) Chemical Principles of Environmental Pollution, Blackie Academic & Professional, London.
Bedient, P.B., Rifai, H.S. and Newell, C.J. (1994) Groundwater Contamination Transport and Remediation, Prentice Hall, New Jersey.
Domenico, P.A. and Schwartz, F.W. (1998) Physical and Chemical Hydrogeology, John Wiley & Sons, New York, Chapters 20, 21.
Dunnivant, F.M. and Anders, E. (2006) A Basic Introduction to Pollutant Fate and Transport, Wiley Interscience, New Jersey.
Harrison, R.M. (ed) 2001, Pollution Causes, Effects and Control, Fourth Edition, Royal Society of Chemistry, Cambridge.
Hemond, H.F. and Fechner-Levy, E.J. (2000) Chemical Fate and Transport in the Environment, Second Edition, Academic Press, San Diego.
Hester, R.E. and Harrison, R.M. (eds) (1997) Contaminated Land and its Reclamation, Royal Society of Chemistry, Information Services, Cambridge.
Nathanail, C.P. and Bardos, R.P. (2004), Reclamation of Contaminated Land, John Wiley and Sons Ltd, Chichester.
Pichtel, J. (2007) Fundamentals of Site Remediation for Metal and Hydrocarbon Contaminated Soils (2nd ed), Government Institutes, Lanham, Maryland.
Pinder, G.F. & Celia, M.A. (2006) Subsurface Hydrology, Wiley Interscience, Hoboken, New Jersey.
Schwartz, F.W. and Zhang, H. (2003) Fundamentals of Groundwater, John Wiley & Sons, New Jersey.
Todd, D.K. and Mays, L.W. (2005) Groundwater Hydrology (3rd edition), John Wiley & Sons, New Jersey.
Waldron, H.A. (1973) Lead Poisoning in the Ancient World, Medical History, London, 17, 391-399.