Hazardous Substances and Contaminated Land

Question 1

How do hazardous substances impact ?

Answer 1

it is the point/diffuse/pathway/receptor model

Question 2

what is the key impact of heavy metals, lead and mercury?

Answer 2

• neurological damage
• effects on mental development (particularly the young)

Question 3

what is the key impact of Chlorinated pesticides (eg DDT)

Answer 3

• concentrates in food chains
• egg shell thinning in birds (leading to failure of reproduction)

Question 4

what is the key impact of PCBs (polychlorinated biphenyls)

Answer 4

• suspected human carcinogen
• impact on aquatic environment
• general chronic effects

Question 5

what is the key impact of CFCs

Answer 5

reduction in stratospheric ozone leading too higher levels of UV light to the earths surface

Question 6

what is the key impact of SOx and NOx

Answer 6

• acidification of upland lakes and rivers
• decline in fish population
• changes to pH levels
• disruption of ecological balance

Question 7

what is the key impact of released disowns from uncontrolled incineration of certain substances

Answer 7

cancer and reproductive anomalies in humans and other species

Question 8

what is the key impact of non-biodegradable detergents

Answer 8

• foaming in rivers
• effects on aquatic life

Question 9

what is the key impact of Oestrogen activity of some chemicals, such as phthalates

Answer 9

• effects on reproduction
• viability of male fish
• possible effects one humans

Question 10

What legislation governs the classification, information-supply and packaging of dangerous substances?

Answer 10

European Regulation (EC1272/2008) on Classification, Loading and Packaging of Substances and Mixtures

(CLP)

Question 11

What is included in CLP?

Answer 11

• hazard statements
• precautionary statements - covering prevention, response, storage and disposal)
• specific pictograms MUST be included - they are in the shape of a red diamond with a white background

Question 12

What is a pesticide?

Answer 12

refers to products that control insects, other animals, weeds or disease-causing micro-organisms that can damage agricultural crops and garden plants.

Question 13

define biocide

Answer 13

a product that controls harmful organisms in other situations eg household insecticide, wood preservatives and disinfectants

Question 14

what could be the key environmental impacts associated with pesticides?

Answer 14

• effects on non-pest species
• sopray drift
• residue in food
• groundwater contamination
• poisoning

Question 15

what is the WHO Pesticide Evaluation Scheme (WHOPES)?

Answer 15

key purpose to promote and co-ordinate the testing and evaluation of pesticides in the interests of public health

has a four phase testing and evaluation programme to
-determine safety/efficacy/operqtionalk acceptability of public health pesticides/specifications for international trade and quality control

Question 16

What are the main objectives of WHOPES?

Answer 16

• to search for alternatives pesticide technologies and methods of application that are safe and cost effective
• design and promotion of guidelines, strategy and policies that promote the correct selection and application of pesticides and to assist and monitor their application by Member States

Question 17

what is the definition of contaminated land under the Environmental Protection Act 1990 Part IIA

Answer 17

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 being caused or there is a significant possibility of such harm being caused or
(b) pollution of controlled waters is being, or is likely to be caused

Question 18

what are some of the environmental impacts of contaminated land?

Answer 18

• direct risk to human health by ingestion
• toxic substances entering the food chain through plant uptake
• water contamination
• prevention or inhibition of plant growth
• odours, fume4s, and effluvia, particularly when gases (landfill gases) percolate the site
• fire and explosion
• direct contact with, or inghalation of, certain contaminants
• building damage

Question 19

what re the major ground water contaminants?

Answer 19

• nitrates and pesticides from agriculture
• dense non-aqueous phase liquids (DNAPL) such as chlorinated solvents
• Light non-aqueous phase liquids (LNAPL) such as hydrocarbons

can spread further than the original spill and persist for decades

Question 20

How can land contamination occur?

Answer 20

• accidents
• leakage
• emissions to the air
• transfer of ground or surface water
• movement of toxic or explosive gases
• building demolition
• waste disposal

Question 21

describe the process of contaminated land investigation

Answer 21

• Phase I - preliminary investigation (desk study and site reconnaissance)
• Phase II - site investigation
• Phase III - remediation

Question 22

describe the preliminary site sampling aims

Answer 22

• locate underground pipes, storage tanks and other structures and determine their contents
• locate, identify and measure soil contamination
• detect, identify and measure gas or vapour migration from underground storage tanks, landfill or other sources

this is aimed at providing sufficient information to plan a comprehensive sampling exercise - the techniques involve only limited sampling

Question 23

describe the comprehensive sampling exercise following the preliminary sampling

Answer 23

designed to measure the presence of contaminants across the site and to determine, within stated confidence limits, the location of hot spots or areas of higher levels of contaminants

important as this will allow the remediation measures to be designed

Question 24

explain the ‘fitness for purpose’ approach

Answer 24

a UK adoption for the management and assessment of contaminated land

Question 25

review the contaminated land risk assessment process and draw it

Answer 25

page 94 of the revision booklet

Question 26

explain Generic Assessment Criteria (GACs)

Answer 26

screening tool for the assessment of contaminated land.

The key GAC are Category 4 screening levels provide a simple test to decide whether the land is suitable for use and not officially contaminated

Question 27

explain Contaminated Land Exposure Assessment (CLEA)

Answer 27

Uses a series of equations to predict, or simulate, exposure to receptors from a given soil concentration via number of exposure pathways.

Question 28

describe the remedial techniques for Contaminated Soil and Groundwater

Answer 28

• establish what is affected - is the pollution in the unsaturated layer above an aquifer, in an aquifer, or both
• decide on the remedial techniques

Question 29

described the remediation strategy

Answer 29

depending upon the
- type of contaminant
- its depth and concentration
- the type of site
- access
- buildings

Question 30

what are some examples of the Remediation Methods

Answer 30

• physical - excavate land and dispose/use membranes or sheet piling to create a barrier between contamination source and target/de-gassing if an organic pollutant
• biological - bioremediation using bacteria for organic pollutants/bioconcentration using plants to take up and concentrate pollutants and then dispose of the plants
• chemical - solidification where a binder such as cement is used to encapsulate the contaminated soil/chemicals used to react with and neutralise the pollutant
• incineration - contaminated soil can be incinerated at 800 - 1500 degrees centigrade

Question 31

Describe Groundwater Remediation Treatment

Answer 31

chemical or physical depending upon the precise contamination

groundwater treatment is very difficult and may be too expensive to undertake