Alert: Waste Spill
Environmental Science
Artesian well
Artesian Well

There are two broad classes of drilled-well
types, based on the type of aquifer the
well is in:

Shallow or unconfined wells are
completed in the uppermost saturated
aquifer at that location (the upper
unconfined aquifer).

Deep or confined wells are sunk
through an impermeable layer into an
aquifer that is sandwiched between two
impermeable strata

The majority of deep aquifers are
classified as artesian wells.
Ground water well

Artesian wells are …
where the water is confined
under pressure below layers
of relatively impermeable
rock.
Artesian Well
Situation…
You are a geologist for the Clear Hydro
Environmental Geology Company.
You receive this urgent email message from
a Lake County Illinois Conservation
officer:
Geologist…studies land
formations, rocks and soil

Complaints from residents near Round
Lake re: unusual odors coming from their
well water.

Residents informed that a tanker was
carrying liquid chemical waste had an
accident and overturned a month ago.
URGENT MESSAGE FROM LAKE COUNT
CONSERVATION BOARD!!

Concern: Waste spill has infiltrated into
the groundwater and has contaminated
wells of the 15 residents.

Wells sites #1 and #2 complaints of odors
and funny-tasting well water. Residents
were told not to drink the water from their
wells. Possible health risk.
URGENT WATER WARNING!!
Geologists Action Required:
Part A: Identify soil layers & properties
1. Label Maps #2 with the soil properties.
2. Review Map 3 and understand well
layouts and the direction of water flow.
3. Color in Map 3 with data from Table 3 on
the different layers of soil within the
groundwater topographical profile.
URGENT-WATER WARNING!
4. Conduct well-water analysis where you
determine the extent of the groundwater
pollution plume.
5. Record your findings and make a
recommendation to the Lake County
Conservation Board on which wells are
contaminated.
URGENT- WATER WARNING!
How a well is dug
Urban and suburban toxic waste sites usually arise from:
industrial operations
leaking underground storage tanks and pipes (such as
from gas stations)
c.
municipal dump sites
d.
leaking hazardous waste storage sites, and perhaps
e.
contamination left over from closed military bases.

a.
b.
The severity of groundwater contamination depends on
characteristics of the waste or leachate (e.g., volume,
composition, solubility, concentration of various
constituents, time rate of release of contaminants, the
size of the area from which the contaminants emanate,
groundwater pumping and recharge, and other factors).

Major concerns at a polluted site is:
1. The migration of contaminants offsite to
the underground aquifer, where they can
pollute the groundwater.
2. Many communities pump groundwater
for their drinking water and these
contaminants can severely compromise
its quality.
Vocabulary:
 Plume: A featherlike structure, form, or
object, generally narrow at its origin and
spreading out as it progresses.


Dispersion: process of leachate moving
out from original source. Theoretically,
plumes will be conically shaped - the
exact shape depending on contaminant
and soil properties

Infiltration: Flowing into the ground or
aquifer. Surface water will usually
infiltrate if the soil is permeable. Rainfall
helps contaminants infiltrate the soil and
possibly move into the aquifer and
groundwater.

Hydraulic gradient: The slope of the
water table. The groundwater flows
downhill and the gradient determines the
rate of flow.

Maximum Contaminant Level (MCL):
The maximum level of certain
contaminants permitted in drinking water
supplied by a public water system as set
by EPA under the federal Safe Drinking
Water Act.
Plume A
Plume B
How are they different?
Plume C
Plume D
Different types of plumes
 What
types of conditions
affect a plume?
1. Porosity and permeability of the soil
2. Rate of groundwater infiltrating the soil
Location: Round Lake Illinois
Topography