Sustainable Geoenvironmental Engineering Practice - Sustainable Practices in Geoenvironmental Engineering - page 466

Oil spills and pipeline leaks may also contaminate the soil and groundwater. Drilling
mud stored in improperly lined pits may also leak into the soil. Well blowouts from over-
pressurized zones can lead to spreading of the petroleum on the surface of the land or
water if at sea. On March 29, 1980, 468,000 tonnes of crude oil (the largest one in history)
rushed into the Gulf of Mexico after a blowout, thereby affecting Mexican and Texas
beaches. Approximately 0.8% of the oil reached the Texas shoreline, with about 5% of the
original amount remaining after one year (Payne and Phillips, 1985).
Another more signiicant event in 2010, one the largest oil spills, known as the Deepwater
Horizon oil spill, occurred in the Gulf of Mexico when 780,000 m 3 of oil were released from
an oil well blowout and explosion until the oil rig was capped after over 87 days. Despite
the beach and wetland protection via loating booms, skimmer ships, controlled burners,
and a dispersant addition, which has been anecdotally reported as seeming to increase oil
toxicity substantially, marine wildlife, ishing, tourism, the economy, and human health
were adversely affected.
At Lac Megantic in the Province of Quebec in Canada on July 6, 2013, a runaway freight
train loaded with crude oil derailed and exploded, killing 47 people and destroying half
of the downtown region. More than 30 buildings were destroyed from the ire including
many irreplaceable historic buildings. Oil contamination of the land affected more than
31 ha (Beaudin, 2013). It has been estimated that more than 558,000 tonnes of soil will need
to be decontaminated. More than 100,000 L of oil reached the Chaudiere River and traveled
more than 80 km. The total cost is estimated at $190 million for the remediation of water
and soil in the area.
Tanacredi (1999) reports that as a result of human development, 115,000 ha of wetlands
are removed each year, in the United States. Less than 40% of the area remains compared
with preindustrial times. Depletion of peatlands alone causes emissions of up to 0.8 billion
tonnes of carbon a year, much of which could be avoided through restoration (Environment
Directorate-General and the Joint Research Centre [JRC] of the European Commission,
2010). A striking example of an unplanned event that occurred in Europe is the construc-
tion of a dam for energy purposes in Slovakia that caused the Szigetkoz marsh (500 m 2 ) in
Hungary to dry up, depriving 5000 species of lora and fauna of a habitat.
Another impact from human activity includes soil sealing, which is the covering of soil
with an impermeable material. This leads to the loss of soil functions such as water iltra-
tion and storage, and food production. Over the 1990s, in the EU more than 1000 km² of
soil were lost per year. From 2000 to 2006, the EU average loss increased by 3%, but in
some countries the rate was higher such as in Ireland and Cyprus (14%), and in Spain
(15%) (European Commission, 2014a). Nineteen EU member states lost a potential agricul-
tural production capability equivalent to a total of 6.1 million tonnes of wheat (1990-2006)
(Gardi et al., 2011). Soil biodiversity is another aspect that must be protected as it provides
a release of nutrients for use by plants and other organisms, assists in the removal of con-
taminants and pathogens, and participates in the carbon cycle, and is a source of genetic
and chemical resources (European Commission Joint Research Centre, 2013). Soil biodi-
versity is highly threatened in areas of high population density and/or areas of intense
agricultural activity.
13.2.2 Wastes and Discharges
In the United States, medical wastes make up approximately 0.3% to 2% of the MSW stream
(USEPA, 1990). The infectious waste is estimated by the EPA at 2 to 3 million tonnes/year
(GGHC, 2008). High-income countries generate up to 0.5 kg of hazardous waste per person