B. Migration pathways of pollutants
The pollutants in the groundwater environment of the site mainly come from the
percolate and other substances produced during treatment of domestic refuses in the
landfill. They permeate through the soil into the groundwater and contaminate it, at
a penetrating effect influenced by local soil and hydrological environment. The
local groundwater vulnerability is fairly high, according to the groundwater vulnerability assessment of the Old Port domestic waste landfill site. Therefore, the
groundwater in the area is prone to contamination by the percolate from landfill.
After the groundwater is polluted, the pollutants will be further migrated and
transformed with the flow of groundwater, and be diffused as well.
C. Receptor
The pollutants in the groundwater will subject the workers in the landfill and the
residents in surrounding areas to exposure risks during operation of the landfill.
Therefore the workers and the residents will be identified as the sensitive receptors,
based on the operation of the Old Port landfill and the residential population
measure of surrounding areas.
III. Analysis of exposure pathways
The groundwater at the site will not be used as drinking water but may be inhaled as
indoor and outdoor groundwater vapors in terms of exposure means. Most of the
pollutants currently of interest in the site are not volatile, and the concentrations of
the pollutants naphthalene and cyanide are far lower than the screening level for
human health protection. Therefore, it is determined that the toxic and harmful
pollutants in the groundwater of the site will not be exposed to the receptor in any
way, or will only present risks to human health at an acceptable level.
④ Conclusions
According to the current situation of the site, the groundwater of the site will not
pose any health risk or only pose risks at acceptable levels to the receptors, which is
identified to be the workers of the site and the residents in the surrounding area.
(2) Groundwater pollution risks assessment in typical sites with polluted
groundwater
The groundwater vulnerability of the landfill site is assessed by the DRASTIC
model. The individual indexes for the groundwater vulnerability of the landfill site
are assessed, according to the data in the environmental impact assessment report of
the domestic refuse landfill site of Shanghai city, with the results as shown in
Table 5.116.
The DRASTIC model analysis shows that the groundwater vulnerability of the
domestic refuse landfill site is “fairly high”. The primary reason is that the surface
pollutants are apt to permeate into the soil, get into and pollute the groundwater, for
344
5 Application Cases
The pollutants in the groundwater environment of the site mainly come from the
percolate and other substances produced during treatment of domestic refuses in the
landfill. They permeate through the soil into the groundwater and contaminate it, at
a penetrating effect influenced by local soil and hydrological environment. The
local groundwater vulnerability is fairly high, according to the groundwater vulnerability assessment of the Old Port domestic waste landfill site. Therefore, the
groundwater in the area is prone to contamination by the percolate from landfill.
After the groundwater is polluted, the pollutants will be further migrated and
transformed with the flow of groundwater, and be diffused as well.
C. Receptor
The pollutants in the groundwater will subject the workers in the landfill and the
residents in surrounding areas to exposure risks during operation of the landfill.
Therefore the workers and the residents will be identified as the sensitive receptors,
based on the operation of the Old Port landfill and the residential population
measure of surrounding areas.
III. Analysis of exposure pathways
The groundwater at the site will not be used as drinking water but may be inhaled as
indoor and outdoor groundwater vapors in terms of exposure means. Most of the
pollutants currently of interest in the site are not volatile, and the concentrations of
the pollutants naphthalene and cyanide are far lower than the screening level for
human health protection. Therefore, it is determined that the toxic and harmful
pollutants in the groundwater of the site will not be exposed to the receptor in any
way, or will only present risks to human health at an acceptable level.
④ Conclusions
According to the current situation of the site, the groundwater of the site will not
pose any health risk or only pose risks at acceptable levels to the receptors, which is
identified to be the workers of the site and the residents in the surrounding area.
(2) Groundwater pollution risks assessment in typical sites with polluted
groundwater
The groundwater vulnerability of the landfill site is assessed by the DRASTIC
model. The individual indexes for the groundwater vulnerability of the landfill site
are assessed, according to the data in the environmental impact assessment report of
the domestic refuse landfill site of Shanghai city, with the results as shown in
Table 5.116.
The DRASTIC model analysis shows that the groundwater vulnerability of the
domestic refuse landfill site is “fairly high”. The primary reason is that the surface
pollutants are apt to permeate into the soil, get into and pollute the groundwater, for
344
5 Application Cases