Intro to Environmental Engineering Lab
Water Treatment Plant Visit
CE 374-102
April 9, 2018
Shadi Alzahrani
UNIVERSITY OF SOUTH ALABAMA
DEPARTMENT OF
CIVIL, COASTAL AND ENVIRONMENTAL
ENGINEERING
150 Jaguar Drive, Shelby Hall 3142
Mobile, Alabama 36688-0002
Telephone: (251)460-6174
Facsimile: (251) 461-1400
http://www.southalabama.edu
April 9, 2018
Arka Pandit, Ph.D.
Department of Civil, Coastal and Environmental Engineering
University of South Alabama
Subject: CE 374 Intro to Environmental Engineering – Water Treatment Plant Visit
Dr. Pandit,
The class had the chance to visit one of two water treatment plants that supplies a clean drinking
water to Mobile county in the state of Alabama. Those Two water treatment plant have been
improved by the Alabama Department of Environmental Management who are maintain the
treatment standards that above the required average that was given by the U.S Environmental
Protection Agency (EPA) for the protection of the health of public. The visit was made to H.E.
Myers Water Plant that located on 1475 Hubert Pierce Road in Semmes, Alabama on March
21,2018 with a group of 18 students who arrived there at 2:40pm with Dr. Pandit. H.E. Myers
Water Plant supplies between 12 and 14 million gallons of a clean drinking water per day since
1990. The group took a tour in the area and saw the process of eight steps of how to treat and
supply the water to Mobile county from where the water comes from Big Creek Lake until the
water gets to people houses. The Big Creek Lake uses as the source of the water to the entire area
and also, known as J.B Reservoir and has been builit in 1952 with a 3,600 acre.
The eight steps of treating and supplying water can be described as follow:
1- Raw Water Intake: where the water transmitted through 60 inch pipes from Big Creek
Lake and dropped in a 40 million gallon tanks before supplies. Four of 48 inch pipes are
used to transmit the raw water from the tanks to the treatment facility.
2- Pre- treatment: is the second step where the powder activated carbon is used for odor and
taste control. Next, adjust the pH with lime (Ca(OH)2) to deal with any irons in the water.
The main of this step is to prepare the water for any change that occur in the pH during the
coagulation stage.
3-
Appendix
We visited Myers Water Plant Feb 20 2017. This water treatment plant was located at 1475
Hubert Pierce Rd Mobile Alabama.
Raw Water Intake
This plant provides drinking water and sanitary sewer service for more than 200,000 people in
Mobile. The source of drinking water is the J.B.Converse Reservoir, which is the Big Creek
Lake. The lake is located in the western part of Mobile County. The 3,600 acre reservoir,
completed in 1952, holds 17 billion gallons and is continually fed by groundwater, streams and
rainfall.Water is delivered from the 3,600 acre lake and pumping station by means of two 60inch diameter pipes to reservoirs at the H.E. Myers and E.M. Stickney Water Treatment Plants.
Pretreatment
The purpose of the pretreatment is to prevent the introduction of pollutants into the wastewater
system. This process protect the wastewater collection system and sewage treatment plants.
Coagulation
In water treatment, coagulation occurs when a coagulant is added to water to "destabilize"
colloidal suspensions. During this process things are easily separated from the water. Add a
chemical such as alum which produces positive charges to neutralize the negative charges on
the particles. Then the particles can stick together, forming larger particles which are more
easily removed.
Flocculation
The water flows into a tank with paddles that provide slow mixing and bring the small particles
together to form larger particles called flocs. Mixing is done quite slowly and gently in the
flocculation step.
Sedimentation
The water flows to a tank called a sedimentation basin where gravity causes the flocs to settle
to the bottom. Things that are heavier sink faster during this process.
Filtration
The filtration apparatus is a concrete box which contains sand, gravel, and an underdrain.
During this process sand does the filtering, gravel keeps the sand from getting out, underdrain
is where the filtered water exits. After the filter is operated for a while, water can not go throw
those layer. Then this system need a backwashing.
Disinfection
After the particles removed, only thing left is to provide disinfection so that no pathogens remain
in the water. Bacteria and viruses are now destroyed by addition of a disinfectant, chlorine.
Enough chlorine is added so that some remains to go out in the water distribution system,
protecting the public once the water leaves the plant.
University of South Alabama
Department of Civil Engineering
Lab #4
Water Treatment Plant
By
Xiao Li
Abdrllah Alqarqah
Asim Aljahdli
Ali Alshehri
CE-370-101
Introduction to Environmental Engineering
Submitted on March 3rd 2017
H.E. Myers Filtration Plant Field Report
Intro to Environmental Engineering Lab
CE 374-102
March 3, 2017
Josué Pérez
Daniel Boudreaux
Clayton Weaver
The following includes a report on the Myers
Water Treatment Plant and what was learned
from this visit. The research team visited this
water plant on February 22, 2017, located on
1475 Hubert Pierce Road in Semmes, AL. Myers
is one of the two water treatment plants that
supply water to the entire area. During this visit, the team toured the area and learned the eight
steps in the process of treating the water and supplying it. These steps include the following: raw
water intake, pre-treatment, coagulation, flocculation, sedimentation, filtration, disinfection, and
sludge handling.
The first step of the process is raw water intake. The treatment plant uses Big Creek Lake, which
is a 3,600 acre lake, as their water source, and this lake also supplies water to treatment plant on
Moffet Road. The plant has a forty million gallon reservoir on site to store the water used from
the lake. The water is supplied by a sixty inch raw water line from the lake to the four raw water
pumps on site.
The second step in the water treatment process is the pre-treatment stage. The water is first
treated with powder activated carbon. This is used for taste and odor control. It works by
absorbing the organics of the water. Then, the water is treated with chlorine dioxide. Chlorine
dioxide is an oxidant designed to remove iron and manganese ions in the water. It is also used
for taste and odor control to make sure the water is satisfying to the consumers. The final
product used to treat the water is lime which is used to raise the pH. The raw water the plant
receives from the lake usually has a pH of 6, so they try to raise the pH a bit, keeping it close to
7.
After the pre-treatment stage, the water goes thru coagulation.
In this process, Alum is used as the coagulant. Alum carries a
positive charge which reacts and sticks to the negative materials
of the water to start forming a floc. These chemicals are mixed
with the water, thru the in-line mixers that mix everything
quickly.
The next step in the water treatment plant is flocculation. In
this step, the plant has two flocculation basins for two different
stages at two different rpms. In the first stage, the water is put
through fast mixing. Once the water goes through the weirs, the
flocculators in the next stage will slow the mixing down, where
the flocs are visible. The retention time in these two tanks is about
thirty minutes.
In the next step, which is sedimentation, the water is then
deposited into the two settling basins. Each basin holds about a
million gallons of water. It takes about 4 to 5 hours for the floc to
settle. The floc was visible in the beginning of the two basins and
as the team walked along the basins, the water began to get clearer.
The basins had weirs in the end for the clean water to go through,
and the sediments that settle at the bottom are collected through
vacuum suction tubes.
The next step in water treatment is filtration. Once the water goes
through the weirs, the water plant adds lime again. After that, the
water runs over the top of the filter system. This step is to collect
any materials that did not settle during the sedimentation stage.
This is to double check the water is clear to go to the next stage.
The seventh step is disinfection. This is where the treatment plant adds the finished water
chemicals. Firstly, they add a corrosion inhibitor to the water for the piping system. Also,
chlorine is added as the disinfectant during this process. After this final process, the pH of the
water is about 7.5 leaving the facility. The plant has 3 high service pumps to pump out the water
to the distribution system.
The last stage in this water treatment is sludge handling. In this stage, the plant has three
centrifuges in a separate building to concentrate the sediments collected. The sediments and
sludge are then placed in trucks and disposed and landfills.
These are the eight steps the H.E. Myers Filtration Plants uses in its water treatment plants. The
team was able to learn about these stages during the tour of the water plant and was able to get an
actual view of the entire process in treating water.
Attached is a sketch of the water treatment plant created using AutoCAD.
CE 374 Introduction to Environmental Engineering
Myers Water Treatment Plant Field Report
Hamad Alyami, Jeremy Widemire, Mohammad Hammam, Philip Crawley
3/3/2017
Introduction:
This water treatment plant field was initiated on February 20, 2017, in which the team involved
visited one of the two water treatment plants that treats and supplies the city of Mobile, Alabama
with a clean drinking water. The water treatment plant has been in operation since 1990 and
currently treats on average of 12-14 million gallons of water per day to un upward capacity of 30
million gallons per day in case if the growing population of West Mobile area demands it. This
water treatment plant is located on 1475 Hubert Pierce Rd, and is named the H.E. Myers Filtration
Plant. This capable water treatment plant’s final treated water undergoes many processes to
ensures its suitability of consumption by the people of Mobile. These orderly process, from the
first pumping of the raw water from Big Creek Lake to the final distribution of clean water and the
many process in between that is happening on or inside of the H.E. Myers water treatment plant
are as follows:
1. Raw Water Intake: Water is supplied via 60 inch pipes from Big Creek Lake and then
stored in a 40 million gallon reservoir before treatments. Four 48 inch pipes pump the
stored raw water from the reservoir to the inside of treatment facility for the next step.
Pictured above are the pumps that bring the water into the treatment plant.
2.
Pretreatment: Powder activated carbon is used then is is treated with lime (Ca(OH)2) to
adjust the pH and deal with any irons in the water. This is needed to prepare the water for the pH
change that will occur during the coagulation stage. All of the chemicals are stored in silos outside
as shown here.
3.
Coagulation: Alum is added at roughly 2048mL/min as a coagulant then the water flows
through the static mixes within the pipes. The mixers are similar to baffled pipes. The Alum bonds
with any particulates dissolved in the water and then these bonds lump together. This helps reduce
the turbidity of the water.
4.
Flocculation: Now the water is flowing into the flocculators. There are two stages for
flocculation. Stage one has a high RPM rate and stage 2 has a slower RPM rate. The first stage is
a bit faster to ensure the Alum is mixed evenly through the water, the second stage is slower to
allow the Alum bonded particles to begin to lump together in larger quantities called flocs before
ultimately
ending
up
in
the
sedimentation
tank.
5.
Sedimentation: Immediately after flocculation the water is deposited into 1 of 6
sedimentation tanks each 1.5 million gallons in volume. The tanks also have vacuum systems that
removes the Alum flocs. After sedimentation the water should now have a much lower turbidity
than before and is ready for filtration. Between the sedimentation tanks and the filtration stage
lime is added again to further balance out the pH. Since lime has some solids in it it is added before
the
filtration
stage.
The
lime
also
increases
the
turbidity
slightly.
6.
Filtration: This stage removes any further Alum flocs as well as any other particles, like
lime chunks, from the water. After filtration the water should be clear. The filters used are large
rapid sand filters. The filter has several layers to it, the first layer is a very fine sand like material
that is called anthracite. The second level is a more traditional sand. The third layer is comprised
of many small pebble like stones and the fourth layer has slightly larger stones. After enough water
is filtered the flow rate of the filters begins to slow and they have to be back washed. The backwash
process causes the filters to lose some of it’s top layer but not a large amount.
Here is a cross section of the filters.
7.
Disinfection: During the disinfection stage finished water chemicals are added. A corrosion
inhibitor is added to protect the pipes that the water is going to be pumped through. Chlorine is
added as a disinfectant to kill any bacteria or viruses are in the the water. Fluoride is also added as
a further disinfectant. The pH of the finished water is risen all the way to 9.4 prior to the addition
of the finished water chemicals. After the chemicals are added the pH drops to about 7.5.
8.
Sludge Handling: The vacuumed flocs and the material back washed from the filters are
pumped into a sludge pool for onsite storage. Then the sludge is put into one of two centrifuges
where the water is removed by the spinning of the material. The leftover solids are then moved via
trucks into the local landfill. Testing is done to ensure that the material is safe for landfill deposits.
Pictured below is a layout of the plant.
It is important to note that there is a control room in this plant. It has all the necessary
computers and software to make sure everything in the treatment process is going according to
plan. Another part of the water treatment is regular testing of the water to determine if it is up to
standards. Pictured below are some of the equipment and testing apparatus used for such tasks.
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