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Design of Small Water Systems
Overview
In this course the student
will review EM 1110-2-503, "Design of Small Water Systems"
published by the U.S. Army Corps of Engineers. This course is particularly
relevant to engineers involved in designing both public and private water
systems. Although the publication's title suggests coverage of only small
water systems, much of the discussion applies to large systems as well.
Below is a summary of the material covered by this course.
The student must take a multiple-choice quiz consisting of
forty questions at the end of this course to earn PDH credits.
Water Quality
The National Safe Drinking Water Act (SDWA) specifies
maximum permissible levels of contamination and minimum monitoring frequencies
for public water systems. Mandatory adherence to the specified maximum
contaminant level (MCL) is dependent on whether the water system serves a
community (year-round residents) or a transient population (such as parks,
campgrounds and restaurants). The MCLs are designed to protect the public
from potential health effects of long-term exposure to contaminants, so they are
generally not applicable to transient populations. Additionally, the EPA
has developed National Secondary Drinking Water Regulations that are intended to
serve as guidelines for the states and are not enforceable at the Federal level.
These guidelines address contaminants that primarily affect the aesthetic
qualities relating to public acceptance of drinking water.
This chapter teaches the following specific knowledge and
skills:
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The National Safe Drinking Water Act's purpose and its
applicability to water systems serving different populations
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Maximum contaminant levels (MCLs) and maximum
contaminant level goals (MCLGs) for microbials, organics, inorganics and
radionuclides
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Secondary maximum contaminant levels (SMCL's) that
affect the aesthetic qualities of drinking water
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Waterborne diseases and methods for detection and
treatment of the water supply
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The prevalence of the most common contaminants in
different water sources (surface vs. ground water), their impact on public
health and aesthetic water quality and typical removal methods.
Water Quantity
Local water shortages are a
recurring problem in many parts of the U.S. and throughout the world. As
the population continues to grow, the problems will only increase. Thus,
it is important to properly plan water use projects to ensure that the system is
capable of meeting the users' demands for many years to come.
This chapter teaches the following specific knowledge and
skills:
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General design criteria for raw water, finished water
and distribution storage
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Design considerations and typical water usage rates for
municipal and rural water systems, as well as recreation areas.
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The effects of water conservation on future water
consumption
Water Sources
When selecting the source for
a small water system, the design engineer must consider many factors including
the quantity and quality of water from the source, as well as development,
operation, maintenance and monitoring costs. Connection to an existing
water system is usually the best option when it is economically feasible.
However, development of groundwater or surface water resources will be necessary
for some applications, particularly in undeveloped areas where existing water
systems are not available.
This chapter teaches the following specific knowledge and
skills:
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The different sources of water available and their
relative merits
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The benefits and methodology of performing sanitary
surveys of alternative water sources prior to selection
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The advantages, disadvantages and design considerations
associated with connection to an existing water system.
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Design considerations for groundwater resource
development including well design, testing and disinfection
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Types of surface water sources and their relative
merits, as well as suction intake design.
Water Treatment
The purpose of water
treatment is to do whatever is necessary to render a raw water suitable for its
intended use. Depending on the quality of the water source and the
intended use, treatment may range from simple disinfection with chlorine to more
expensive, specialized processes such as reverse osmosis or ion exchange
treatment. This chapter examines the more common water treatment problems
and addresses the most likely means of treatment. Emphasis is placed on
identifying the base available technologies (BAT) for treating small water
systems, although much of the material is also applicable to large water
systems.
This chapter teaches the following specific knowledge and
skills:
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Best available
technologies for drinking water contaminant removal
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Relative merits of
disinfection technologies, including chlorination, iodination, ozonation, and
UV radiation
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Iron removal techniques,
including polyphosphates, ion exchange and oxidation-filtration
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Acceptable hardness levels
and hardness removal using ion exchange softening
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Taste and odor removal
using aeration, adsorption, oxidation and source water management techniques
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Water stabilization and
corrosion control
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Turbidity removal using
coagulation/flocculation, sedimentation and filtration
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Total dissolved solids (TDS)
removal using reverse osmosis and ion exchange
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Control of organic
substances
Pumping Storage and
Distribution
Small water systems have
unique design considerations relative to larger municipal water systems.
The small number of users makes the system more sensitive to peak rates demanded
by one or several users. Given this fact, it is particularly important
that the system designer consider all components of the system simultaneously.
This chapter teaches the following specific knowledge and
skills:
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Design considerations and sequence for designing a water
pumping, storage and distribution system
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Factors to consider when selecting a pump and designing
a pumping station
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Different types of storage tanks available and their
relative merits
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Distribution pipe sizing, layout, material selection,
support and testing.
Course
Click on the following PDF attachment to review EM
1110-2-503, "Design of Small Water Systems" prior to taking a quiz for credit.
The quiz will be based only on material covered in Chapters 3 thru 7.
Note that there are 8 quiz questions for each
chapter and the quiz covers the material sequentially by chapter. Thus,
Questions 1 thru 8 cover Chapter 3, Questions 9 thru 16 cover Chapter 4, etc.
"Design
of Small Water Systems" (468 KB)
Having Trouble Downloading the PDF File?
Right click on the link. Select "Save Target As..."
Then save on your desktop. To view the file, double click the icon on your
desktop and return to this page to take the quiz.
You may need Acrobat Reader to view this document.
Click on the link below to download a free copy of Acrobat Reader.
Note that the PDF file attached above contains
the entire document EM 1110-2-503. If you would like to download the
document by individual chapter, visit the Army Corps of Engineers website at the following URL:
http://www.usace.army.mil/publications/eng-manuals/em1110-2-503/toc.htm
To obtain PDH credits for this course, you will need to take a quiz for
credit. Click on the link below.
(To take the quiz,
your web browser must be set to accept cookies. See how to
check your cookie settings.)
 
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