CONSTRUCTION & INDUSTRIAL: WHITE CAP
Course 29, Level 1
Drain Assembly
Slide 1: Welcome
Thank you for your interest in Drain Assembly. The Associate who successfully completes this course will
understand the importance and purpose of surface water management and stormwater drainage;
common types of drainage systems and their applications; and installation methods, materials, and
jobsite safety precautions.
Slide 2: Features
Before we begin, let us point out a few features.
On the left, you’ll see two tabs. Use the Notes tab to follow this narration. Click on the Menu tab to track
your progress. You can click on a section or page to navigate back to it.
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comments or ask questions. Click on Resources to download the script and additional resources. Click on
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On the bottom, there are two buttons: the Previous and Next buttons. Use the Next button to advance to
the next page. Use the Previous button to go back to a previous page.
Click the Next button to advance to the next page.
Slide 3: Recommended Connection
To ensure a successful online connection, we recommend the following:
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Use a wired broadband connection.
Keep ALL windows associated with the course open. If a window opens in your browser as you’re
starting the course, leave it open.
Close all other programs.
Slide 4: Course Progress
PLEASE NOTE: This program tracks your course progress so that you can save your session and return
at a later time. If you are presented with an error message while completing or exiting the course, please
email wctrade@hdsupply.com.
Slide 5: Course Agenda
This course is separated into four sections: Surface Water Management, Drainage Systems, Drainage
Materials, and Drainage Applications & Jobsite Safety. We recommend that you take notes to help you
retain the information presented.
After each section, there will be a short assessment. You’ll have to pass the assessment before
advancing to the next section.
Slide 6: Learning Objectives
By the end of this course, you will:
1.
2.
3.
4.
Understand the importance and purpose of surface water management and stormwater drainage.
Learn about common types of drainage systems.
Learn about drain pipes, fittings, materials, and structures.
Learn installation methods for different drainage applications and jobsite safety precautions.
SECTION 1: Surface Water Management
Slide 7
Section 1 will cover the importance and purpose of surface water management and stormwater drainage.
Slide 8
Without proper drainage, precipitation may flow over land or impervious surfaces instead of percolating into
the ground. This excess water, called stormwater runoff, may collect and lead to flooding, presenting
dangers to property and people.
Stormwater runoff can also cause erosion and carry harmful materials like chemicals, fertilizers, pesticides,
animal waste, gas, and oil from land, building rooftops, paved streets, and parking lots (if discharged
untreated) can make streams, lakes, and rivers unsafe for drinking, swimming, fishing, and other activities.
Slide 9
Amendments to the federal Clean Water Act require the Environmental Protection Agency (EPA) to
regulate stormwater discharges. The primary method to control stormwater discharges is by a Surface
Water Management (SWM) system (required by the Clean Water Act) that consists of a collection of open
channels, drainage swales, detention and retention facilities, and enclosed conduits that comprise the
overall drainage system for an area or region.
Slide 10
Practically every jurisdiction in the U.S. has to comply with the Clean Water Act and have a Surface
Water Management system in place. Many cities and towns have planned stormwater drainage systems
designed to control the quantity, quality, timing, and distribution of runoff. New developments of a certain
size are required to have flow and water quality control facilities to store and clean runoff from their
impervious surfaces.
Slide 11
In Canada, the federal government passed the Canada Water Act in 1970 and created the Department of
the Environment in 1971, entrusting the Inland Waters Directorate with providing national leadership for
freshwater management. Under the Constitution Act (1867), the provinces are "owners" of the water
resources and have wide responsibilities in their day-to-day management. All provinces and territories in
Canada have their own environmental statutes and pollution control regulations. Ideally, polluting
contaminants should be prevented from entering the water.
The Clean Water Act (2006) protects existing and future sources of drinking water and sets out a basic
framework for the establishment of community-based groups that represent a cross section of sectors and
geographic areas within Conservation Authority (Canada) boundaries.
Under the Fisheries Act, the federal government regulates water pollution and prohibits any discharge of
a “deleterious substance” into water frequented by fish. Provinces regulate discharges into and takings of
fresh water, including groundwater. Typically, the discharge of pollutants is prohibited, unless permits or
approvals have been issued. The pollutants that are controlled include a wide variety of toxics, as well as
human waste, liquids, and debris. Municipal sewer use by-laws usually govern discharges of liquid waste
into a municipal sewer.
Slide 12
Stormwater drainage systems collect surface runoff via inlets covered by protective grates in road
pavements and usually route it through underground pipes to a treatment unit and/or receiving body of
water. The outfall is where the stormwater exits the storm drainage system. Pipe outlets are constructed in
various shapes, sizes and materials. The most commonly used are round and oval pipes made from
reinforced concrete, corrugated metal, or plastic. Ditches and low-lying or depressed stretches of land
(swales) often lined with concrete, rocks, or grass also are used as outlets to convey stormwater into and
out of the storm system from pipes.
Slide 13
In construction projects, the civil engineer is usually responsible for the drainage system. Most
jurisdictions have drainage laws that govern to what degree a landowner can alter the drainage on their
land. Land developers are responsible both during and after construction to provide, install, and maintain
appropriate erosion control measures and other stormwater Best Management Practices (BMPs) to
minimize any adverse impact to water quality or the local environment. BMPs are techniques, measures,
or structural controls used to manage the quantity and improve the quality of stormwater runoff. The goal
is to reduce or eliminate the contaminants collected by stormwater as it moves into streams and rivers to
protect and improve them. BMPs also help protect wetlands, ecosystems, and help manage flood control.
Slide 14: Section 1 Summary
This section discussed the importance and purpose of surface water management and stormwater
drainage.
You learned that without proper drainage, excess water, called stormwater runoff, may lead to flooding,
erosion, and harmful materials being deposited into public water systems, which is why this runoff is
regulated by the Clean Water Act.
You also learned that the primary method to control stormwater runoff is with a Surface Water
Management (SWM) system entailing stormwater drainage, which collects surface runoff through
underground pipes via inlets.
Additionally, you learned that the civil engineer is responsible for the drainage system in construction
projects and that land developers are responsible for maintaining stormwater Best Management Practices
(BMPs) on their developments.
Slide 15 Section 1 Assessment
This short assessment will test your knowledge of Surface Water Management and Stormwater Drainage.
You must correctly answer at least six out of eight questions to advance to Section 2. You will receive
feedback after answering each question. If you do not pass on your first attempt, that’s OK. You will be
directed to the beginning of the section where you can review the concepts before re-attempting the
assessment. Click Next to begin.
SECTION 2: Drainage Systems
Slide 16
Section 2 will cover common types of drainage systems.
Slide 17
Drainage falls under plumbing systems, which are subject to municipal and local codes that mandate
certain plumbing practices be followed on the job. While local plumbing codes vary by jurisdiction
throughout the United States, plumbers and contractors usually adhere to the Uniform Plumbing Code
(UPC) requirements that govern the installation and inspection of plumbing systems. The UPC is a model
code developed and regularly updated by the International Association of Plumbing and Mechanical
Officials (IAPMO).
The key to selecting a successful drainage system is in understanding what it must accomplish. Some
common purposes are:
1.
2.
3.
4.
Control of water on roadways for traffic safety
Prevent water invasion into structures or equipment
Collect and store harmful fluids for human/environmental protection
Remove water for pedestrian safety
Slide 18
It is important to select the right drainage system for the site’s particular soil type. A soil’s permeability can
be measured to provide its hydraulic conductivity, which will determine drainage selection. Topography,
rainfall, and soil type all influence drainage system selection, as do product availability, durability, and
cost.
The soil’s limitations and potentials are classified according to drainage classes, which refer to the
frequency and duration of wet periods similar to those under which the soil was formed. The class
indicates the degree, frequency, and duration of wetness, which factor into rating soils for various uses.
There are seven classes of natural soil drainage:
1.
2.
3.
4.
5.
6.
7.
Excessively drained
Somewhat excessively drained
Well drained
Moderately well drained
Somewhat poorly drained
Poorly drained
Very poorly drained
Slide 19
The type of drainage system required will determine pipe selection and its required strength. Selection of
pipe strength requires determining the dead load of the soil above the pipe (earth load), the live load
applied to the soil surface, the selection and determination of the bedding factor, and a safety factor.
Load classes for pipes are classified according to:
 Class A – Pedestrians
 Class B – Cars/light trucks
 Class C – Heavy duty forklifts/tractor trailers
 Class D – Heavy duty hard tire forklifts
Slide 20
Pipes are rated for the volume of internal flow as an N-value, which is used in the Manning formula for
calculating the hydraulic capacity of drain pipes for gravity and pressure flows: The lower the N-value, the
greater the volume of flow. (The Manning’s formula provides the basis of the hydraulic design
consideration for corrugated high-density polyethylene (HDPE) and polypropylene (PP) pipe.)
Slide 21: INTERACTION – Drain Types (Tab Interaction)
Click on the tabs above to hear about common drain types. Please note that the narration will provide
additional information to the text that is presented on the screen. This additional information is available to
download by using the Resources link at the top right.
Surface Drains
Storm drains are designed to handle excess water as a result of flooding or heavy rainfall and are
usually located on either side of a street at a low point in the road where water would naturally collect.
They typically are covered by a grate and are available with precast or custom built drain basins.
French drains (also known as blind drains) typically are used to prevent surface and ground water from
penetrating buildings and foundations and to relieve ground water pressure behind retaining walls. They
consist of a slightly sloped trench filled with a pipe and either sand, gravel and geotextile, or landscaping
textile to prevent pipe clogging, that then divert water away from a structure. French drains are usually
buried around the external side of foundation walls or underneath or on the inside perimeter of basement
floors. Water runs into the trench, then typically into a perforated pipe at the bottom of the trench that
drains along its length discharging surplus water into either low-lying areas, a drainage ditch, a dry well,
or the street.
Trench Drains
Trench drains (also known as channel drains) are channel-shaped linear floor drains with grating
systems used for rapid evacuation of surface water. They typically are used when perimeter drains are
needed for hardscaped areas and are made from corrosion-resistant polymer concrete, fiberglass, or
steel.
Cast-in-place trench drains entail building a trench with wood forms, attaching drainage pipes to the
suspended forms, filling the trench with concrete, removing the forms, and placing grates in the frame.
Modular trench drain systems allow the drain pipe to be connected anywhere along the trench and
typically are used in applications such as pools and pedestrian and public areas.
Former trench drains use forms made of lightweight expanded polystyrene (EPS) or cardboard. Forms
attach to a prefabricated frame and grate system that is set in the trough and aligned for concrete
pouring. The forms are removed after the concrete has cured.
Pre-cast concrete trench drains are factory made, usually of polymer concrete, in forms that typically
have a pre-determined channel width, depth, and slope. Custom trench drains are also available.
Linear (LINE) drains remove water along their entire length, rather than at one particular point and are
made from polymer concrete, fiberglass, or structural plastic and steel. Most linear drains are variations
on an enclosed channel, typically with a u-shaped cross-section and a grating over the top. Types ranges
from simple units to combined kerb and drainage systems in materials ranging from polymer concrete,
wet-press concrete, HDPE, and stainless steel. Linear drains with built-in falls are used to drain large, flat
areas. Linear drains with regular depth along their length are used for short drain lengths in areas with a
natural slope or fall. Gratings come in galvanized, heavy duty plastic (polypropylene), ductile iron,
stainless steel, resin polymers, and milled aluminum.
KlassikDrain are general purpose modular channel trench drain systems whose components consist of
polymer concrete drainage channels in 4-inch (K100), 8-inch (K200), and 12-inch(K300) internal widths
with either a galvanized or stainless steel edge rail. All systems have 130-foot continuous slope with a
wide choice of grates ranging from Class A pedestrian to Class E industrial heavy duty. KlassikDrains are
used in drainage applications such as carparks and shopping centers. The polymer concrete channels
are available with standard polyester or optional vinyl ester resin binders, reinforced by mineral
aggregates and fillers. The polymer has a low moisture absorption rate, a lower friction coefficient,
superior hydraulic performance and compressive strength, and is resilient to repeated freeze-thaw cycles.
Slide 22: INTERACTION - Drain Types
PowerDrain is a slim, heavy-duty sloped trench drain system made of high-strength polymer concrete in
4-inch (S100K), 8-inch (S200K), and 12-inch (S300K) internal widths complete with grates for applications
requiring a rugged product such as carparks, railway platforms, architectural surfaces, pedestrian zones,
landscaping, and industrial surfaces. A special rubber damping between the trough and grate creates a
noise attenuation when passing the channel. The damping protects the channel body, increasing the life
of the entire gutter system.
Markant drain is a range of building products designed for residential landscapes. DrainLine100 can be
used for driveway drainage and backyard patio applications where it protects both paved and landscaped
areas from stormwater accumulation and debris. HexaDrain Brickslot is a trench drain with a modified
cover for a discreet intake slot instead of a regular grate. DrainMat is a high-quality entrance foot
scrapper and drain in one with galvanized or stainless steel or aluminum grille profiles with rubber inserts.
Sport drains are designed specifically to meet the demands of track and field facilities. Made of highstrength polymer concrete, the drains are designed to protect against injury while ensuring that water is
rapidly drained so that sporting facilities can be used throughout the year. In addition to drainage
channels, the systems include accessories such as rubber-capped kerbs, sand traps, and services boxes.
Infrastructure drainage systems consist of factory manufactured modular channel units made from
eithercorrosion-resistant polymer concrete, fiberglass, or MDPE, together with grates from a variety of
materials for all loading applications.
Utility ducts are a surface ducting system designed to protect cables, pipes, etc. against external
influences. The duct allows continuous access along a cable/pipe route via removable covers. The drains
come in polymer concrete to provide insulation for electrical cables.
Prefabricated drainage systems usually consist of a geotextile fabric that separates the soil from a flat,
flexible polymeric core that channels water to drains that can be connected to standard piping. The larger
surface area conveys a higher volume of water than a typical French drain.
Subsurface Drains
Subsurface drainage is drainage beneath the ground surface and is typically used to drain heavy, poorly
drained soils. The purpose of subsurface drainage is to control the water table level by removing excess
water from the soil. Buried pipe drains usually consist of corrugated, flexible, and perforated plastic
piping wrapped with an envelope or filter material to improve pipe permeability and to prevent entry of soil
particles. Drainage trenchers dig the trench, lay the slotted pipe, and place permeable backfill into the
trench on top of the pipe.
Mole Drains
Mole drains are unlined circular soil channels that function like pipe drains. They are used in heavy soils
where the clay subsoil prevents downward movement of ground water. Mole drainage can be classified
as mole drains, mole drains over a collector pipe system, or gravel mole drains.
A mole plough forms a mole channel that is maintained by the soil’s high clay content and breaks the soil
above the channel to allow it to collect water. Mole drains over a collector pipe system are used in soils
where it is impossible to form moles that reach the outfall. A mole drain is formed over subsurface pipes
that are installed with sand or small diameter gravel backfilled into the pipe trench. Excess ground water
1) flows into and along the mole drains, 2) drains into the porous backfill above the pipes, and 3) is
removed to outfalls via the subsurface collector pipes. Gravel mole drains are used in difficult to drain
soils and situations where subsurface pipes are unsuitable. They consist of an unlined channel filled with
small diameter gravel or sand.
Drainage Options
Point drainage intercepts water at gullies (points) that connect to drainage pipes beneath the ground
surface.
Channel drainage intercepts water along the entire channel in the form of gratings or a single slot.
Slide 23: Section 2 Summary
This section discussed common types of drainage systems. You learned that drainage falls under
plumbing systems and thus must adhere to the Uniform Plumbing Code (UPC). You also learned that the
key to selecting a successful drainage system is in understanding what it must accomplish.
Additionally, you learned that the site’s soil type will determine drainage system selection (which will
determine pipe selection and its required strength); about load classes for pipes; that pipes are rated for
the volume of internal flow as an N-value; and about surface and subsurface drain types.
Slide 24 Section 2 Assessment
This short assessment will test your knowledge of common types of Drainage Systems. You must
correctly answer at least eight out of ten questions to advance to Section 3. You will receive feedback
after answering each question. If you do not pass on your first attempt, that’s OK. You will be directed to
the beginning of the section where you can review the concepts before re-attempting the assessment.
Click Next to begin.
SECTION 3: Drainage Materials
Slide 25
Section 3 will cover common drain pipes, fittings, materials, and structures.
Slide 26
Selecting the proper drainage systems and materials entails understanding where and how the products
will be used. This requires understanding hydraulics, traffic loading, chemical resistance requirements,
environmental factors, and grate properties.
Slide 27
For the purpose of this course, hydraulics entails understanding the flow of liquids in pipes, rivers, and
channels. Calculating drainage (storm water runoff) for a given area entails determining the area’s rainfall
intensity, the amount of water draining from the area in gallons per minute (gpm), and how much water
will have to be stored.
Slide 28
Traffic loading can range from light foot traffic to extremely heavy vehicles and equipment. U.S. standards
reference drain system loading for complete drain systems and individual grates with various required test
parameters.
Load classifications for trench drains, for example, include:






Slide 29
A: up to 3,372 pounds, for residential and light pedestrian traffic
B: up to 28,100 pounds, for sidewalks and small private parking lots
C: up to 56,200 pounds, for parking lots and general commercial use
D: up to 89,920 pounds, for trafficked sections of roads and highways
E: up to 134,800 pounds, for industrial areas, gas stations, and light commercial forklifts
and
F: up to 202,320 pounds, for aircraft pavements, docks, heavy fork trucks, and other
similar wheel loads
The grating selected should meet the chemical resistance requirements for its use. Environmental factors
to consider would be sunlight, which can be destructive to polymers, and freeze/thaw cycles. Stainless
steel grating is typically used in environments prone to oxidation due to extreme heat or chemical attack.
Slide 30
Once hydraulics, loading, chemical resistance, and environmental factors are met, the grates need to
meet user and legislative requirements, including visual and cost preferences.
A variety of visual effects can be attained with grating materials such as stainless steel, ductile iron,
composites, and brass in addition to perforated, slot, mesh, and decorative patterns. A grate can blend
with the pavement or contrast as a feature or border.
The Americans with Disabilities Act of 1990, Section 4.5.4. stipulates open slot sizes and lengths so that
wheelchair wheels and walking aids don’t become trapped or slip on the grate surface.
Slide 31: INTERACTION – Drainage Pipes and Fittings (Tab Interaction)
Click on the tabs above to hear about common drainage pipes and fittings. Please note that the narration
will provide additional information to the text that is presented on the screen. This additional information is
available to download by using the Resources link at the top right.
Drainage Pipes
Reinforced Concrete Pipes (RCP) are designed for storm sewers, sanitary sewer pipe, culverts, and
detention systems. They are the most durable and longest-lasting pipe for underground usage.
Corrugated high-density polyethylene (HDPE) pipes are durable, have a high resistance to corrosion and
chemicals, and have good load carrying capabilities. They come in single-wall pipes for agricultural,
residential, highway culverts and recreational applications. Smooth interior dual-wall pipes are used for
municipal storm drains and highway drainage. Smooth interior dual-wall and triple-wall pipes are available
in polypropylene resin.
Polyvinyl chloride (PVC) pipes are used to transport water and dispose of sewage. When properly
installed, they are impervious to root invasion and crush resistant.
Corrugated metal pipes (CMP) are typically used to convey drainage water underground or from a catch
basin to a surface water. They can come in galvanized steel, aluminized steel, aluminum allow and
polymer coated steel.
Ductile Iron Pipes (DIP) are commonly coated on the inside with a cement-mortar lining so that they can
handle the transporting potable water, sea water, non-septic gravity sewers, sewer force mains, and
reclaimed water. DIP is also available with various epoxy liners for septic sewer and other caustic
environments.
Fittings
A coupling fitting connects two pipes together. If the pipe sizes vary, the coupling may be called a
reducing coupling, reducer, or adapter. Couplers help create a leak-tight pipe seal. Ductile-iron couplings
help to limit pipe expansion and contraction and can also dampen vibration. Grip-L pipe couplings can
create a pull-out resistant seal. Open-flex couplings feature a split gasket design that helps enable
installation without pipe disassembly
An elbow fitting enables a change of direction between two lengths of pipe or tubing, typically at a 90 or
45 degree angle. When two ends differ in size, the elbow is called a reducing elbow or reducer elbow.
A wye is a fitting with three openings used to create branch lines. A standard wye is a "Y"-shaped fitting
that allows one pipe to be joined to another at a 45 degree angle.
Pipe bends are used to change the direction of run of pipe and can match long distance transition
requirements.
Slide 32: INTERACTION – Drainage Pipes and Fittings
A tee is a pipe fitting that is T-shaped with two outlets at 90° to the connection to the main line. It is used
to connect pipes of different diameters or for changing the direction of pipe runs. If a branch line passes
completely through a tee, the fitting becomes a cross tee. A cross tee fitting has one inlet and three
outlets, or vice versa. They often have solvent welded socket ends or female threaded ends.
Saddle tees are used to add a tee in an existing pipe.
A cap is a fitting that covers the end of a pipe by screwing or attaching onto the male thread of a pipe. A
cap may have a solvent weld socket end or a female threaded end and the other end closed off. In
plumbing systems that use threads, the cap has female threads. Industrial caps can be round, square,
rectangular, U-shaped, I-shaped and may have a round hand grip or a flat hand grip
A plug closes off the end of a pipe. It is similar to a cap but it fits inside the fitting it is mated to. In a
threaded iron pipe plumbing system, plugs have male threads.
A union fitting enables quick and convenient disconnection of pipes for maintenance or fixture
replacement.
A nipple fitting is a short piece of pipe with external male pipe threads at each end to connect two other
fittings.
Valves are designed to stop or regulate flow of fluid and are categorized according to their applications
such as isolation, throttling, and non-return. Gate valves, plug valves, and ball valves are used for
isolation only. Globe valves are used for throttling. Butterfly valves and diaphragm valves are used for
isolation as well as throttling. Check valves are used for preventing reverse flow.
Pop-up drainage emitters act as the discharge point of a drainage system, opening easily when needed
to allow water to flow freely from the pipe and away from structural foundations. The spring-loaded cap
opens with the hydrostatic pressure of water flowing through the drain pipe, then closes as the flow
diminishes.
A sewer clean out is a capped pipe that provides access to a sewer line to clean out blockages in the
sewer. The pipe can usually be opened by hand or with a wrench and cleared with a plumbing snake or
augur.
Slide 33 INTERACTION – Drainage Materials and Structures (Tab Interaction)
Click on the tabs above to hear about common drainage materials and structures. Please note that the
narration will provide additional information to the text that is presented on the screen. This additional
information is available to download by using the Resources link at the top right.
Drain Materials
Drainage boards typically are dimpled plastic sheets that keep water from penetrating to the surface of a
wall. Some drainage boards incorporate solid materials that are porous enough to allow water to flow
down. Others use twisted or deformed wire covered with a filter fabric to provide the drainage space.
A drain envelope is a porous material placed around a perforated pipe drain to provide filtering, hydraulic,
mechanical, or bedding functions to enhance pipe performance.
Storm drain filters remove phosphorous, hydrocarbons, oil, sediment, silt, and heavy metals from runoff.
Various models can attach to storm drains, pipes, or containment areas to remove unwanted materials so
only cleaner water is allowed to flow off of the site. Options include downspout filters, oil and debris drain
blockers, pipe filter socks, and self-bailers that attach to drains.
Drain Structures
A catch basin is a part of a storm drain or sewer system that is designed to trap debris so that it cannot
enter the drainage pipes and typically is covered with a catch basin grate to keep debris out
Channel grates cover channel drains to keep debris out.
Valve boxes protect in-ground valves and can house single-valve units, multiple valves, or other
subsurface components.
Water meter boxes are used to protect water meters from destruction, theft, or wear and tear.
Manholes allow easy access to underground piping, meters, and facilities.
Slide 34: INTERACTION – Drain Materials and Structures
Spill containment is a process that confines materials when spills or overflows occur to minimize the
impact on the environment. They can be a component of a sewage system, or an inflatable unit
positioned on site. Spill containment structures can include filter pads, containment drums, and
containment sumps for pumping waste.
Permeable pavers allow stormwater to percolate directly into the ground in areas that would traditionally
be impervious, significantly reducing runoff, controlling pollutants, and reducing downstream erosion.
Sump pumps are water pumps intended as a water drainage system for basements and concrete
foundations. Submersible pumps remove water from a sump pit (a well dug under the basement), and
carry it away from the structure. Pedestal pumps are above ground sump pumps that pump water upwards into overhead vats. Groundwater naturally drains into the sump pit via gravity or a perimeter
channel around the basement foundation that channels the water into the sump pit.
Slide 35: Section 3 Summary
This section discussed common drain pipes, fittings, materials, and structures. You learned that selecting
the proper drainage systems and materials entails understanding where and how the products will be
used, which requires knowing hydraulics, traffic loading, chemical resistance provisions, environmental
factors, and user and legislative requirements. Additionally, you learned about different drain pipes,
fittings, materials, and structures.
Slide 36: Section 3 Assessment
This short assessment will test your knowledge of common Drainage Materials. You must correctly
answer at least eight out of ten questions to advance to Section 4. You will receive feedback after
answering each question. If you do not pass on your first attempt, that’s OK. You will be directed to the
beginning of the section where you can review the concepts before re-attempting the assessment. Click
Next to begin.
SECTION 4: Drainage Applications
Slide 37
Section 4 will cover installation methods for different drainage applications and jobsite safety precautions.
Slide 38
Developing land by covering it with structures, roads, and other impervious covers prevents the
underlying soil from absorbing rainfall. That causes the water to pool which can spill over into structures.
To address this, many counties require drainage plans to control rainwater that runs off of developed
land.
A drainage plan is a proposed method for containing rainwater on property and typically is required before
a building permit is issued. A drainage plan should be drawn in advance of construction and all drainage
materials should be inspected prior to and during installation.
Common methods of controlling runoff from roofs, for example, is to run the water into downspouts that
run into a drywell if the property can accommodate it. If the soil is sufficiently permeable a conventional
septic system or a pressurized sewage disposal system usually suffices as a drainage plan. If the soil is
not sufficiently permeable, alternative drainage plans can include detention ponds, underground storage
tanks, and infiltration trenches and berms.
Slide 39
Residential drainage requires down spouts. To avoid large amounts of water collecting in small areas
near concrete foundations, down spouts can be connected to a drainage system that relocates the water
off the property, or to a swale (a natural grass area designed to channel water from one area to another),
or to culverts under driveways or along roads, which have a pipe and inlet or catch basin.Trenches for
down spout drains can be 16 inches deep and should follow the contouring of the ground. Soil or sod can
be used to cover the piping.
Slide 40
A French drain system or some version of it typically is used to drain water away from unwanted
collection areas to more suitable areas. In certain areas, the water in the drain can be absorbed back into
the ground. The drain also can act as a collection area for other draining systems.
Dry wells, surrounded with drainage fabric and clean stone or as stand-alone, are often used in
conjunction with drainage systems for water storage and re-absorption.
Channel drains may be required in the concrete or asphalt of driveways to alleviate flooding. Cut into the
driveway to catch running water or to drain standing water, channel drains usually connect to a French
drain system that drains the water to an acceptable location.
Slide 41
Drainage issues can be harmful not only to structures but to landscapes as well. Proper drainage and
irrigation is important to lawns and plants, which can be killed by excess standing water.
Trench drains can be used to carry excess water from wet areas to a designated drainage outlet. Trench
drains rely on gravity and perforated drain piping to redirect water and thus should be built on the high
end of a property.
Wood stakes and string are used to mark waterlogged areas and create a path for drain pipes. Once the
trench is dug with the bottom in a U shape, gravel or some similar product is put into the trench and
spread level. Perforated drain pipes are then placed over the gravel with holes facing up. Elbow
connections are used to join pipes at curves. The pipe is then wrapped in mesh fabric to allow water to
pass through but to block dirt particles from clogging the pipe. Gravel is then placed over the pipe and the
trench is filled with dirt. Pop-up drainage emitters will allow water to be diverted and released to watersafe areas away from structures, erosion-prone landscapes, and poor drainage areas.
Slide 42
In commercial and industrial facilities, the building storm drain should extend outside the building and
connect to the site’s storm sewer system. Building storm drains should be sloped for a minimum water
velocity and to keep sediment and debris suspended. Underground storm sewers should be sized to
allow for future expansion. Stormwater is relieved outside the building through manhole covers, catch
basins, or other exterior storm-drainage inlets.
Slide 43
Only clear-water, non-contaminated drainage suitable for direct discharge into natural waterways should
be connected to the storm drainage system. Water such as clean condensate from air-handler/fan coil
units is acceptable under the Clean Water Act. However discharge of chemically treated, contaminated,
and chlorinated potable water, as well as high-temperature water should be directed to sanitary drains.
Slide 44
Drainage systems should be sized according to the appropriate rainfall rate. A separate gravity drainage
system should be provided for stormwater from roof areas. Any stormwater retention should occur
downstream of the building. The number and size of drains should be able to convey the stormwater from
areas being drained at the same rate as water collects in those areas.
Relief provisions should be incorporated to prevent buildup of water should the primary drain fail. Flat roof
areas can be provided with overflow scuppers or a dedicated secondary emergency roof drainage
overflow system discharging through downspouts. Roof and overflow drains can include sump receivers,
under-deck clamps, and aluminum or cast iron domes. An expansion joint or acceptable horizontal offset
(swing joint) is typically provided at connections to each roof and overflow drain.
Slide 45
Drainage in areas with pavers typically discharge both surface drainage and accumulated flow below the
paver through promenade-type perforated drains. Grates of all area drains should be sufficient for the
anticipated traffic loading.
Slide 46
Underslab sub-soil drainage piping for slab-on-ground and buried structure may be recommended by the
structural engineer. Pump systems may serve subsoil/underslab drainage. Where subsoil drains connect
to the storm drainage system, an exterior sand trap or catch basin is typically provided. An automatic
backwater valve at the sand trap will prevent reverse flow of stormwater into the subsoil drains.
Slide 47
Swimming pools can experience drainage problem when water seeps along outside walls and settles
underneath the pool. Uneven moisture beneath the pool can cause uneven heaving and settling of the
pool. The pool’s walls may pull away from one another, eventually form cracks, and cause leaks from
inside the pool.
A subsurface water-control system such as French drains can minimize the amount of water that can
seep to the bottom of the pool. A sump pump system in an 8-12 foot deep pipe underneath the pool can
remove collected water. Additionally, channel drains in the pool decking will divert incidental water due to
splashing from the pool.
Slide 48
Athletic fields need to be designed for maximum drainage to remove excess water from rainfall before
and during an event. Inadequate drainage can leave the topsoil saturated and the water will pool or run
off. Using the field when the soil is saturated will damage the field and increase the amount of soil
compaction, making the drainage problem worse.
Moisture is commonly removed from athletic fields through surface drainage and an underground
drainage system. Surface drainage removes excess moisture from the field to the sidelines where a
perimeter drain system carries the water to an underground drainage system.
Corrugated HDPE pipe with fine slits in the plastic are typically used to drain athletic fields. Installing drain
lines lengthwise in the field will require less trenching and allow for maximum interception of water flowing
from the center of the field toward the sideline areas of the field.
Slide 49
According to the Occupational Safety and Health Administration (OSHA), two workers are killed every
month in trench collapses. Cave-ins pose the greatest risk. Other potential hazards include falls, falling
loads, hazardous atmospheres, and incidents involving mobile equipment. Trenches five-feet deep or
greater require a protective system unless the excavation is stable rock. OSHA standards require that
employers inspect trenches daily and as conditions change before worker entry to ensure elimination of
excavation hazards. OSHA standards also require safe access and egress to all excavations, including
ladders, steps, ramps, or other safe means of exit for employees working in trench excavations of four
feet.
Underground utilities should be located before digging. Tests should be conducted for atmospheric
hazards such as low oxygen, hazardous fumes, and toxic gases when trenches are four feet deep.
Workers who operate or work near hydraulic excavators and backhoe loaders are at risk of being struck
by the machine or its components or by excavator buckets that detach from the excavator stick.
Machinery should be outfitted with guards.
Slide 50
Personal Protective Equipment (PPE) includes:
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Hard hat for overhead impact or electrical hazards
Eye protection with side shields
Gloves chosen for job hazards expected (e.g., heavy-duty leather work gloves for
handling debris with sharp edges and/or chemical protective gloves appropriate for
chemicals potentially contacted)
ANSI-approved protective footwear
Respiratory protection as necessary—N, R, or P95, filtering facepieces may be used for
nuisance dusts (e.g., dried mud, dirt and silt) and mold (except mold remediation). Filters
with a charcoal layer may be used for odors
High visibility clothing when exposed to vehicular traffic
Slide 51: Section 4 Summary
This section discussed common installation methods for different drainage applications and jobsite safety
precautions. You learned that drainage plans control rainwater that runs off of developed land. You also
learned about installation methods to drain residential, landscape, and commercial/industrial sites as well
as swimming pool areas and athletic fields, in addition to jobsite safety considerations.
Slide 52 Section 4 Assessment
This short assessment will test your knowledge of installation methods for different drainage applications
and jobsite safety precautions. You must correctly answer at least eight out of ten questions. You will
receive feedback after answering each question. If you do not pass on your first attempt, that’s OK. You
will be directed to the beginning of the section where you can review the concepts before re-attempting
the assessment. Click Next to begin.
Slide 53: Congratulations
Congratulations! You have completed Drain Assembly. Before you go, there are a few things we’d like to
share with you.
Slide 54: Course Summary
In this course you learned that without proper drainage, stormwater runoff may lead to flooding, erosion,
and harmful materials being deposited into public water systems. You also learned that stormwater
drainage collects surface runoff through underground pipes via inlets. Additionally, you learned that it is
important to select the right drainage system for a site’s particular soil type; the factors that determine
pipe selection; drain types for surface and subsurface drains; and common drain pipes, fittings, materials,
and structures. You also learned about various drainage applications and jobsite safety hazards.
Slide 55: Recap
You should now be able to:
1.
2.
3.
4.
Understand the importance and purpose of surface water management and stormwater drainage.
Discuss common types of drainage systems.
Explain different drain pipes, fittings, materials, and structures.
Understand installation methods for different drainage applications and jobsite safety precautions.
Slide 56: Thank You!
Thank you for your time. Our core value is customer service. By improving our overall understanding of
the businesses in which our customers work, we can better help them achieve success. Close this
program by clicking Exit at the top right.