Aleks Ifraimov
FRQ - groundwater
1/1/13
Two sources of possible groundwater pollution is first off Septic systems. A
septic system is an on-site method of treating and disposing of sanitary
wastewater. It consists of removing solid from raw wastewater. Septic
systems are used by homes, offices or other buildings that are not connected
to a city sewer system. They are designed to slowly drain away human waste
underground at a slow, harmless rate. An improperly designed, located,
constructed, or maintained septic system can leak bacteria, viruses,
household chemicals, and other contaminants into the groundwater causing
serious problems. Septic systems harm the groundwater When pollutants
from the drain field move too quickly through the soil and potentially into the
groundwater. When there is large volume of wastewater moving through the
system, soils with high permeability can be rapidly overloaded with organic
and inorganic chemicals and microbes, allowing rapid movement of
pollutants into the groundwater. Another source of possible groundwater
pollution is Landfills. Landfills are the places that our garbage is taken to be
buried. Landfills are supposed to have a protective bottom layer to prevent
contaminants from getting into the water. However, if there is no layer or it
is cracked, contaminants from the landfill (car battery acid, paint, household
cleaners, etc.) can make their way down into the groundwater. The
precipitation that falls into a landfill, coupled with any disposed liquid waste,
results in the extraction of the water-soluble compounds and particulate
matter of the waste, and the subsequent formation of leachate. The creation
of leachate, called "garbage soup," presents a major threat to the current
and future quality of groundwater. The leachate can pollute the soil slowly
getting to the groundwater. Groundwater systems cannot cleanse itself as
quickly as flowing surface water can because groundwater flows very
slowly, at a rate of about one foot per day. This means that it cannot
effectively dilute and disperse contaminants. In addition, groundwater often
has a low amount of dissolved oxygen, a property that can help decompose
many contaminates. Low levels of DO, as well as decomposing bacteria,
makes it harder for groundwater to clean itself well. MTBE is used almost
exclusively as a gasoline additive to help reduce harmful tailpipe emissions
from motor vehicles. MTBE has been credited with improving air quality by
significantly reducing carbon monoxide and ozone levels in areas where the
additive has been used. The downside of this is that MTBE became a source
of groundwater pollution in the us. MTBE readily dissolves in water and can
move rapidly through soils and aquifers. Because it is resistant to microbial
degradation, it migrates faster and farther in the ground than other gasoline
components, thus making it is more likely to contaminate public watersupply systems. MTBE was found in 21 percent of 480 wells located in
specific areas of the United States that use MTBE in gasoline to abate air
pollution. In the rest of the United States, MTBE detection frequency in
groundwater was only about 2 percent. This shows that MTBE containments
groundwater greatly. The health impact from this pollutant is unclear but
MTBE has been shown to cause cancer in rats and mice exposed at high
levels via inhalation or gavage. Due to this MTBE should be regarded as
posing a potential carcinogenic risk to humans based on animal cancer data.
The water quality would also be tested by EPA for odor or taste to see if
MTBE is present so they can find a way to remove it. One federal law used to
regulate drinking water in the us is The Safe Drinking Water Act (SDWA) of
1974 and its amendments establishes the basic framework for protecting the
drinking water used by public water systems in the United States. This law
contains requirements for ensuring the safety of the nation's public drinking
water supplies. Public drinking water supplies include water systems which
regularly serve 25 or more people per day or which have at least 15 service
connections. The U.S. EPA sets national standards for drinking water to
protect against health risks, considering available technology and cost. Each
standard also includes monitoring and reporting requirements.