The eLearning Center for Gatlin Education Services

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.

Specific Knowledge or Skill Attained

This course teaches the following specific knowledge and skills:

  · The National Safe Drinking Water Act's purpose and its applicability to water systems serving different populations
  · Maximum contaminant levels (MCLs) and maximum contaminant level goals (MCLGs) for microbials, organics, inorganics and radionuclides
  · Secondary maximum contaminant levels (SMCL's) that affect the aesthetic qualities of drinking water
  · Waterborne diseases and methods for detection and treatment of the water supply
  · 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:

  · General design criteria for raw water, finished water and distribution storage
  · Design considerations and typical water usage rates for municipal and rural water systems, as well as recreation areas
  · 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:

  · The different sources of water available and their relative merits
  · The benefits and methodology of performing sanitary surveys of alternative water sources prior to selection
  · The advantages, disadvantages and design considerations associated with connection to an existing water system
  · Design considerations for groundwater resource development including well design, testing and disinfection
  · 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:

  · Best available technologies for drinking water contaminant removal
  · Relative merits of disinfection technologies, including chlorination, iodination, ozonation, and UV radiation
  · Iron removal techniques, including polyphosphates, ion exchange and oxidation-filtration
  · Acceptable hardness levels and hardness removal using ion exchange softening
  · Taste and odor removal using aeration, adsorption, oxidation and source water management techniques
  · Water stabilization and corrosion control
  · Turbidity removal using coagulation/flocculation, sedimentation and filtration
  · Total dissolved solids (TDS) removal using reverse osmosis and ion exhange
  · 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:

  · Design considerations and sequence for designing a water pumping, storage and distribution system
  · Factors to consider when selecting a pump and designing a pumping station
  · Different types of storage tanks available and their relative merits
  · Distribution pipe sizing, layout, material selection, support and testing

State Board Acceptance

This course can be used by professional engineers to fulfill PDH requirements mandated by state and provincial licensing boards. Decatur Professional Development is an approved provider of continuing education in all states that pre-approve course providers. In all other states that mandate continuing education for engineers, it is the individual engineer's responsibility to determine the suitability of activities for PDH credit. The state boards typically accept online* courses that cover technical, managerial** or ethical content and which are relevant to the practice of engineering. The course must have a clear purpose or objective with a content that will maintain, improve or expand the skills and knowledge of the licensee's field of practice. For questions about your mandatory PDH requirements, visit the website of your state licensing board.

*Online courses are accepted by all state licensing boards that mandate continuing education. Other than New York (which limits online courses to 18 PDH) and Iowa (which limits online courses to 6 PDH), there are no limits placed by other states on the number of hours that can be earned through online continuing education. Consult with your state licensing board if you have any questions about the acceptability of online courses.

**The New York State Board of Engineers does not accept general office management courses, but will accept project management courses that are offered by an approved provider and that are technical in nature and contribute to the engineer's professional practice.