Water Quality and Treatment

113 Pages·2014·6.55 MB·English

by  Orlando Coronell

Water Quality and Treatment

Lessons For
Middle/High School

Prepared by:

Ariel Atkinson, Kasia Grzebyk, Lin Lin, Jingbo Wang,
Orlando Coronell PhD
Department of Environmental Sciences and Engineering
Gillings School of Global Public Health
University of North Carolina at Chapel Hill

Robert Greenberg
Chapel Hill High School, Chapel Hill, North Carolina

June 2014

Outreach Program of the Water Purification Science and Technology Research Group at
UNC-Chapel Hill – Visit us at http://coronell.web.unc.edu/outreach
This packet serves as a guideline for middle/high school teachers to educate students
about drinking water quality and production. Others who plan to hold outreach programs
on water education may also use this as an additional support. This packet is a product of
an outreach program conducted in 2014 at Chapel Hill High School in Chapel Hill, North
Carolina.

This packet contains:
• A description of the purpose, content, and prerequisites for the lessons.
• A day-by-day layout of the outreach lectures, assignments, activities, and other support
materials.
• Sample slides that were used in a series of lectures given in 2014 and instruction for the
corresponding activities.
• Photos that were taken during the outreach in the spring of 2014.

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Purpose
These lessons are designed to help the students learn about water through a combination
of lectures and laboratory activities. The topics include water resource, water quality,
conventional water treatment, and advanced water treatment. These topics aim to help
students understand the importance of clean water, the water quality and regulations in
the US, the latest technologies of drinking water production, and the future of drinking
water supply for the world population.

The following subjects are covered:
Importance of clean water and current water scarcity issues
Water resources for drinking water production
Indications of water quality and regulations
Water quality testing
Conventional water treatment, including coagulation, flocculation, sedimentation,
filtration and disinfection
Advanced water treatment with a focus on membrane technology (which is the authors’
area of expertise )

These lessons meet the following North Carolina public school common course standards:
EEn.2.4.1 Evaluate human influences on freshwater availability
EEn.2.8.2 Critique conventional and sustainable agriculture and aquaculture practices in
terms of their environmental impacts.
EEn.2.8.3 Explain the effects of uncontrolled population growth on the Earth’s resources.
EEn.2.8.4 Evaluate the concept of “reduce, reuse, recycle” in terms of impact on natural
resources.
Bio.2.2.1 Infer how human activities (including population growth, pollution, global
warming, burning of fossil fuels, habitat destruction and introduction of nonnative
species) may impact the environment.
Bio.2.2.2 Explain how the use, protection and conservation of natural resources by
humans impact the environment from one generation to the next.
8.E.1.1 Explain the structure of the hydrosphere including:
• Water distribution on earth
• Local river basin and water availability

3
8.E.1.2 Summarize evidence that Earth’s oceans are a reservoir of nutrients, minerals,
dissolved gases, and life forms:
• Estuaries
• Marine ecosystems
• Upwelling
• Behavior of gases in the marine environment
• Value and sustainability of marine resources
• Deep ocean technology and understandings gained
8.E.1.3 Predict the safety and potability of water supplies in North Carolina based on
physical and biological factors, including:
• Temperature
• Dissolved oxygen
• pH
• Nitrates and phosphates
• Turbidity
• Bio-indicators
8.E.1.4 Conclude that the good health of humans requires:
• Monitoring of the hydrosphere
• Water quality standards
• Methods of water treatment
• Maintaining safe water quality
• Stewardship

Prerequisites
It is suggested students have been introduced to the following concepts before
participating in these lessons:
• Hydrosphere and water cycle (Earth/Environmental Science)
• Health effects of bacteria and viruses (Biology)
• pH, acidic and basic (Chemistry)
• Filtration (Physics)

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Table
 of
 Contents

Day
  Activity/Material
  In-­‐Class
 Time
  Page

Requirement
  Number(s)

Day
  Water
 Quality
 Report
 Card
  15-­‐25
 minutes
  7-­‐14

1
  Water
 Quality
 Report
 Card
  15

Worksheet

Homework-­‐water
 collection
  0
 minutes
  16

Day
  Water
 Quality
 Lecture
 and
  30
 minutes
  18-­‐30

2
  PowerPoint
 with

Compartment
 Bag
 Test
 Part
 1
 and

  10
 minutes
  27

Water
 Quality
 Test
 Strip
 activity
  10-­‐15
 minutes
  29

and
 Homework
 Instructions
  30

Compartment
 Bag
 Test

  31-­‐34

Manufacturer
 Instructions

Water
 Quality
 Test
 Strip
 Activity
  35

Worksheet

Day
  Conventional
 Water
 Treatment

3
  Lecture
 and
 PowerPoint
 with
  40
 minutes
  37-­‐53

Coagulation/
 Flocculation/
  10
 minutes

Sedimentation
 demonstration
  49

Day
  Conventional
 Water
 Treatment
  5
 minutes
  55-­‐59

4
  Review
 Lecture
 and
 PowerPoint

with
 Build-­‐Your-­‐Own
 Multimedia
  30-­‐40
 minutes
  57

Water
 Filter
 Activity
 and

Compartment
 Bag
 Test
 Part
 2
  5-­‐10
 minutes
  58,
 59

Build-­‐Your-­‐Own
 Multimedia
 Water
  60-­‐63

Filter
 Activity
 Worksheets

Day
  Virtual
 Tour
 of
 Advanced
 Water
  65

30-­‐40
 minutes

5
  Treatment
 Plant
 Worksheet

Day
  Advanced
 Water
 Treatment
 Lecture
  30-­‐35
 minutes
  67-­‐108

6
  with
 Low-­‐Pressure
 membrane
  5
 minutes
  90

demonstration

Review
 Quiz
  10-­‐15
 minutes
  109-­‐113

5
Day
 1:
 Local
 Drinking
 Water
 Quality
 Reports

1. Local
 Water
 Quality
 Report
 Card

2. Water
 Quality
 Report
 Card
 Worksheet

3. Water
 Collection
 Homework
 Assignment

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PRSRT STD
U.S. POSTAGE
(cid:20)(cid:18)(cid:19)(cid:20)(cid:57)(cid:67)(cid:86)(cid:71)(cid:84)(cid:51)(cid:87)(cid:67)(cid:78)(cid:75)(cid:86)(cid:91)(cid:53)(cid:72)(cid:83)(cid:82)(cid:85)(cid:87)(cid:38)(cid:68)(cid:85)(cid:71) PERMPAITID NO. 1
ZIP CODE 14304
Orange Water and Sewer Authority, 400 Jones Ferry Road, Carrboro, NC 27510
2012 Water Quality Report
We are pleased to provide this report on the quality of
our drinking water in 2012. We are committed to supplying
excellent water for our community’s quality of life, health
and safety and economic vitality.
In 2012, we treated about 2.6 billion gallons of drinking
water, or 7.3 million gallons per day, in accord with Federal
standards under the Safe Drinking Water Act, and related
State standards.
7(cid:26)
Substances found in the Orange Water
and Sewer Authority’s Drinking Water in 2012
(Public Water System Identification Number: 03-68-010) Please see the definitions on page 3.
Substance MCL Violation? Highest Level Range Highest Level Highest Level Major Source
and Unit Y = yes Detected Detected Allowed Goal in Drinking
Measurement N = no (except as noted) (MCL) (MCLG) Water
Microbiological Substances
Turbidity N 0.497 0.015 to TT = 1 NTU 0.3 A measure of the cloudiness of
(NTU) and 99.9% of 0.497 and 95% of samples water. Turbidity may be caused by
samples below 0.3 below 0.3 inorganic soil particles or
fragments of organic matter that
can interfere with treatment
Radiological Substances
Combined radium N 0.1 no range 5 0 Erosion of natural deposits
(pCi/L) (last tested in 2008)
Inorganic Substances
Fluoride N 0.66 no range 4* 4 Erosion of natural deposits; water
additive which promotes strong
(ppm)
teeth; discharge from fertilizer and
aluminum factories **
* The fluoride level in our water (0.66 of one part per million) was well below the maximum allowed (4 parts per million).
** In accord with Federal requirements, our annual Water Quality Report Cards include a statement that potential sources of fluoride in drinking water include erosion of natural deposits; water additive which
promotes strong teeth; [and] discharge from fertilizer and aluminum. However, there are no fertilizer or aluminum factories in the watersheds of our Cane Creek Reservoir and University Lake.
Sulfate N 24 no range 250 N/A A mineral that occurs naturally
(ppm) [Secondary MCL] in soils
Disinfectants and Disinfection By-products
Total Haloacetic Acids N 22.6 17.0 to 29.0 60 0 By-product of disinfecting drinking
(running yearly (individual (running yearly water with chlorine or chlorine-
(ppb) average) sample sites) average) ammonia compound (chloramines)
Total Trihalomethanes N 31.4 23.7 to 44.7 80 0 By-product of disinfecting drinking
(ppb) (running yearly (individual (running yearly water with chlorine or chlorine-
average) sample sites) average) ammonia compound (chloramines)
Chloroform N 11 no range not regulated not By-product of disinfecting drinking
(ppb) regulated water with chlorine or chlorine-
ammonia compound (chloramines)
Bromodichloromethane N 6.1 no range not regulated not By-product of disinfecting drinking
(ppb) regulated water with chlorine or chlorine-
ammonia compound (chloramines)
Chlorodibromomethane N 1.5 no range not regulated not By-product of disinfecting drinking
(ppb) regulated water with chlorine or chlorine-
ammonia compound (chloramines)
Chloramines N 2.9 0.1 to 3.9 MRDL = 4 MRDLG = 4 Compound of chlorine and
(ppm) (average for Jan., (range for ammonia used to disinfect water
Feb. and Jan., Feb. and
April-Dec.) April-Dec.)
Chlorine N 1.17 0.02 to 2.03 MRDL = 4 MRDL = 4 Compound of chlorine
(ppm) (average during (range during and ammonia used
chlorine-only chlorine-only to disinfect water
disinfection disinfection in
in March.) March.)
Disinfection By-product Precursors
Total Organic Carbon N 1.77 1.09 to 2.53 TT = Removal ratio N/A Naturally present
(removal ratio) – greater than in environment
or equal to 1.0
TREATED WATER
The presence of contaminants does not necessarily indicate that water poses a health risk.
8(cid:27)
Page 2
DEFINITIONS of words and phrases in the table of substances found in our water
Maximum Contaminant Level Goal (MCLG) - the level of a 90th Percentile – the contaminant level which 90 percent of the
contaminant in drinking water below which there is no known or samples for a given water characteristic were below. The 90th
expected risk to health. MCLGs allow for a margin of safety. percentile level is the required reporting unit for lead and copper.
Maximum Contaminant Level (MCL) - the highest level of a Below Detectable Level (BDL) - a concentration below the level
contaminant that is allowed in drinking water. MCLs are set as that can be detected using accepted laboratory methods.
close to the MCLGs as feasible using the best available treatment
technology. MCLs are set at very stringent levels. A person would Maximum Residual Disinfection Level Goal (MRDLG) - the level
have to drink 2 liters (about two quarts) of water at the MCL level of a drinking water disinfectant below which there is no known
every day for a lifetime to have a one-in-a-million chance of or expected risk to health. MRDLGs do not reflect the benefits of
having adverse health effects from many regulated contaminants. using disinfectants to control microbial contaminants.
Secondary Maximum Contaminant Level - a guideline for Maximum Residual Disinfectant Level (MRDL) - the highest level
aesthetic (taste and odor), rather than health purposes. of a disinfectant allowed in drinking water. Disinfection is neces-
sary to control microbial contaminants (germs) in drinking water.
Parts per million (ppm) - one part per million corresponds to about
one minute in two years, or one penny in $10,000. One ppm is Disinfection by-products - substances such as haloacetic acids
equivalent to 1 milligram per liter (mg/L). and trihalomethanes, which are formed when chlorine or chlora-
mines used to disinfect drinking water react with organic com-
Parts per billion (ppb) - one part per billion corresponds to about pounds naturally present in lake water. Federal standards require
one minute in 2,000 years, or one penny in $10 million. One ppb is public water systems to limit the levels of haloacetic acids and
equivalent to 1 microgram per liter (ug/L). trihalomethanes because they could be harmful at high levels.
Nephelometric Turbidity Unit (NTU) - a measure of cloudiness Disinfection by-product precursors - organic carbon compounds
in water. Turbidity over 5 NTU is barely noticeable to the that can combine with disinfectants (chlorine and chloramines) to
average person. form haloacetic acids and trihalomethanes as discussed above.
Action Level (AL) - the concentration of a contaminant which, Removal Ratio - measure of the effectiveness of total organic
if exceeded, triggers treatment or other requirements which a carbon removal during our water treatment process. This ratio
water system must follow. should be greater than or equal to 1.0. The Removal Ratio is the
Federally required reporting unit for total organic carbon.
Treatment Technique (TT) - a required process intended to
reduce the level of a contaminant in drinking water. Picocuries per liter (pCi/L) - a measure of the radioactivity in
water. (A picocurie is one trillionth of a curie.)
Drinking Water Treatment
Supply Treatment Distribution
8
4
3 5
1
2
6 7
1 Pump Station 3 Clarification 5 Filtration 7 Clearwell 8 Water Tower
Untreated water from University Water then flows to either Water flows down through The water flows to our 1.5 million The elevated tanks maintain water
Lake or the Cane Creek Reservoir a “pulsator” or settling filters with layers of sand gallon “clearwell” tank for pressure so that drinking water can
is pumped to our Jones Ferry basins, where solids settle and anthracite coal, where temporary storage. Ammonia be delivered to your tap through
Road Water Treatment Plant. out of the water. additional particles are is added to the water and the our network of more than 380 miles
removed from the water. ammonia combines with chlorine of public water mains. The water
2 Mixing 4 Disinfection tdois fionrfmec “t cthhelo wraamteinr.e Ws”a ttoe rf uisrther taavnakilsa abllseo t oh efilgph et nfisreusre a tnhda tt ow mateeert i s
When the water enters our plant, As water flows to filters, 6 Post Treatment then pumped to our water peak demand by our customers.
powdered carbon and alum are chlorine in the form of We add fluoride for dental storage tanks.
mixed into the water to make liquid bleach is added for health, and a chemical to set
solid particles clump together initial disinfection. the pH (acidity/alkalinity) of
and to improve the taste and the water at the right level.
odor of the water. 9
Page 3
Lead and Your Health
If present, elevated levels of lead can cause serious health problems, especially for pregnant women and young children. Lead in
drinking water is primarily from materials and components associated with service lines and home plumbing. OWASA is responsible
for providing high quality drinking water, but cannot control the variety of materials used in plumbing components. Plumbing code
limits for lead in solder and fixtures were tightened in 1986 to reduce the potential for lead to dissolve from pipes, solder or fixtures
into drinking water.
When your water has been sitting for several hours, you can minimize the potential for lead exposure by running water for 30
seconds to 2 minutes before using water for drinking or cooking.
If you are concerned about lead in your water, you may wish to have your water tested (please see additional information below).
Information on lead in drinking water, testing methods, and steps you can take to minimize exposure is available from the
EPA’s Safe Drinking Water Hotline, 800.426.4791, or at www.epa.gov/safewater/lead.
TESTING Our Drinking Water for Lead
The Federal limit on lead in drinking water is a maximum of 15 and 1985. The results from this testing in 2011 were all below the
parts per billion in at least 90% of the samples tested. (One part detectable level of 3 parts per billion.
per billion corresponds to one penny in $10 million.) Our testing
results are significantly better than this standard. In response to customers’ requests in 2012, we tested tap water
for lead in 12 homes. In all of the water samples, lead was below
We regularly test our water as it leaves the Jones Ferry Road the detectable level of 3 ppb.
Water Treatment Plant. For over 10 years, all of these test results
have been less than the detectable level of 3 parts per billion. For more information, including how you can have the water in
In accord with Federal and State standards, we also test every your home tested for lead at no charge, please contact the OWASA
three years for lead in tap water at 30 homes built between 1983 Laboratory staff at 919.537.4227 or [email protected].
GETTING INVOLVED in Water Quality and Supply Issues
You can get involved in water resource issues at the local, State and national level.
• Being informed is the first step in being an effective participant.
• You can learn about water and water resource issues from news media; books in the library; websites such as those of the U.S.
Environmental Protection Agency, American Water Works Association and other organizations; and by contacting OWASA
(telephone: [phone]; e-mail: [email protected]; website: www.owasa.org).
• If you have an e-mail address, we would be glad to send you our electronic notices and news releases about OWASA-related
topics of interest to you. We invite you to contact OWASA Public Affairs at 919.537.4267 or [email protected] about the topics
you are interested in.
• Expressing your views at public meetings, by contacting public officials, etc. is important when improvements, plans, policies and
standards affecting water quality and watershed protection are needed or proposed.
We invite you to attend and participate in meetings of the OWASA Board of Directors, which makes decisions on plans and policies
and adopts the annual budget for our water and wastewater services. The OWASA Board meets at 7 PM on second Thursdays of
most months in the Community Room on the lower floor of the OWASA Administration Building, 400 Jones Ferry Road, Carrboro; and
on fourth Thursdays at the Chapel Hill Town Hall. On fourth Thursdays, OWASA Board meetings are televised live on channel 18 of
the cable television systems serving Chapel Hill and Carrboro.
Tip!
If you are a residential customer and you use more than an average of 4,000 gallons per month, feel free to contact us or visit
our website for information on conservation opportunities.
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