This information is intended to help students, employees, and visitors in the University of Michigan community understand how the University’s stormwater system operates, what the laws require, and what you can do to reduce contamination in the stormwater system from surface runoff. As you move through the information you will learn more about stormwater, what you can do to help, how the regulations impact our operation, and various safe practices.
This information was developed as a joint effort between the U-M Department of Occupational Safety and Environmental Health and the School of Natural Resources and Environment. Comments should be directed to Steve O'Rielly. We all need to help prevent contamination through stormwater, hence Our motto: Stormwater: Our Resource, Our Responsibility.
We take many things for granted in our modern world. One of these is our ability to develop an area into a thriving community and provide an infrastructure to effectively move stormwater away from buildings and living areas. This ability places a tremendous responsibility on all of us to ensure the water moves through our space, to the river, in a condition that will not adversely impact the natural environment.
What is stormwater? Stormwater is exactly what it sounds like! Stormwater is the water resulting from rainfall and storms.
When it rains, stormwater can move in three ways:
- Rainfall can evaporate and go back into the atmosphere,
- Rainfall can infiltrate and nourish plants trees and can also replenish groundwater.
- Rainfall can runoff as "stormwater runoff." Stormwater runoff occurs in areas where surfaces do not allow for infiltration. Such surfaces are called impermeable or impervious, as they do not allow for water to permeate into the ground. Examples of impermeable surfaces include: parking lots, sidewalks, roads, and rooftops.
Picture courtesy of The U.S. EPA
Figure 1. Shows how runoff is increased (from 10% runoff to 55% runoff) with increases in impervious surfaces associated with urbanization.
Common Pollutants in Stormwater Runoff
Of evaporation, infiltration, and runoff, stormwater runoff is the least desirable. Stormwater runoff has been shown to cause a myriad of environmental and safety hazards such as: soil erosion, degraded lakes and streams, algal blooms and fish kills, and flooding.
Typically, as cities grow and urban sprawl continues to rise, more and more impermeable surfaces result in increased stormwater runoff. As the runoff travels across these impermeable surfaces, it collects pollutants such as dirt/sediment, motor oils, fuels and metals from vehicular use, trash, and nutrients from fertilizer. This polluted runoff then enters stormwater inlets, where it moves through a series of underground pipes, and ultimately discharges, untreated, into surface waters such as rivers, lakes, streams, or wetlands.
In addition to the direct negative impact of the pollutants, runoff discharges often contain large volumes of water, travel at high velocities, and can cause stream levels/depths to rise rapidly. The increased stream flow often results in rapid erosion of stream banks and quickly degrades wildlife species and their habitat. To summarize, here is a list of pollutants and relative impacts associated with stormwater runoff:
- Nutrients (Nitrogen, Phosphorus, etc.) - can cause algal blooms which may have a direct impact on water recreation and fishing (and thus tourism and the economy). Algal blooms are not only physically harmful to the environment; they are also visually degrading and often smell bad.
- Trace Metals - are often bound to sediments in stormwater runoff and may pose a threat to both the environment and human health.
- Sediment/Trash/Debris - as with nutrients, sediment and debris can result in degraded aquatic habitat and health. This impacts water recreation and the environment.
- Oil/Grease - results in degraded aquatic life and habitat and reduces the aesthetic appeal of waterbodies and can be harmful to the environment and human health.
- Salt - results in degraded aquatic life.
- E.Coli and other Bacteria - excess E.Coli and bacteria are harmful to human health and, when elevated, may result in beach closures.
Another (commonly overlooked) negative impact of stormwater runoff is an increased cost to treat drinking water. Most drinking water is taken from natural sources such as lakes and reservoirs and the more polluted these waters are, the more difficult and costly it is to treat the water to meet drinking water standards.
Decreasing Stormwater Pollution at the U
Decreasing stormwater pollution is a responsibility shared by all members of the community. In both our work and private lives, we all must adopt measures to control the pollutants. Some people have jobs that involve direct responsibility for the reduction of stormwater pollution; however, everyone should utilize environmentally sound practices both inside and outside of the workplace, during everyday activities, in order to keep our waters clean. Students, staff, faculty, vendors, and visitors at the University of Michigan should be concerned about stormwater pollution, both on and off campus. Remember, pollution is difficult to handle once it occurs. It is easier and less expensive to control pollution before it happens, rather than to clean it up afterwards.
In the pages that follow, you will discover the many facets of stormwater. You will see how University employees can reduce stormwater pollution throughout daily operations. You will also find the special programs and investigations the University is implementing in an effort to determine and eliminate the sources of stormwater pollution on campus. But, most importantly, you will learn what you can do at home and at work to help reduce the pollution of our surface waters.
We all need to do our part to:
"Keep our Michigan Waters BLUE!"
If a spill occurs and it is safe to respond, do so immediately. Secure the area with “Caution – Do Not Enter” tape, rope, or warning signs and inform your supervisor as well as others in the immediate area of the spill. Block any drains that could be impacted by the spill. This can be done using spill response materials such as a spill mat, drain plug, or berm. If these materials are not available, the drain can be blocked using any materials on hand, such as plastic garbage bags tucked around the drain or dirt piled around the drain to form a berm.
If assistance is required, contact UM OSEH at 3-4568 or the Department of Public Safety (DPS) at 911 or 3-1131. OSEH have response vehicle and materials for emergencies on campus.
If the spill is of a known material and is something you are comfortable cleaning up, then clean up the spill according to your department's emergency spill response procedures. When cleaning up a spill, be sure to protect yourself with any necessary personal protective equipment; familiarize yourself with the material safety data sheet for the spilled material; and be aware of any potential hazards associated with the clean up. When the spilled material has been cleaned up, place any contaminated materials in a sealed container. DO NOT dispose of spill debris or contaminated protective equipment into the general trash, down a drain, or into the ground. Never wash spilled materials down a storm drain or sanitary sewer, or allow them to evaporate. If any spilled material enters a storm drain or sanitary sewer, contact OSEH at 3-4568. The materials used to clean up any spill must be disposed of properly through OSEH. DO NOT place them in the dumpster . Contact OSEH at 3-4568 for proper disposal.
If improper dumping or discharge is observed on University property, immediately notify OSEH at 7-1143, or DPS at 3-1131. Report any off-campus dumping into Ann Arbor storm drains to the City of Ann Arbor Water Utilities Department at 994-1760.
Keep the staff in your department updated on emergency response procedures and conduct periodic review sessions. A copy of your department's procedures should be kept in your work area, including whom to contact in case of a spill, an evacuation route, and the location of spill response materials.
Train employees in advance on when and how to use spill response materials properly. Assign a person to test clean-up equipment periodically and maintain its inventory.
Rubber mats, temporary drain plugs, or berms should be kept in the area so drains can be blocked immediately. For small spills, use a chemical spill pillow or adsorbent material appropriate for the spill. For non-hazardous materials, adsorbents that can be swept or picked up such as sawdust, vermiculite, oil-dry, or activated charcoal may be used. Avoid the use of cat litter, it is relatively non-absorbent and increases waste volume.
If you have any questions or need assistance contact OSEH at 7-1143.
The Stormwater Management Program Plan (SWMPP) is prepared as a requirement of the University’s National Pollutant Discharge Elimination System (NPDES) Stormwater Discharge Permit. This permit is issued to the University of Michigan (UM) by the Michigan Department Environmental Quality (MDEQ). Our SWMPP describes measures, procedures and practices that UM will utilize to minimize the discharge of pollutants from campus into the stormwater drainage systems and adjacent receiving waters. In accordance with the Permit, the SWMPP is required to include the following topics:
- Public education and outreach program(s) on stormwater impacts
- Public involvement and participation
- Illicit discharge elimination program for the campus
- Post-construction stormwater management program for new development and redevelopment projects
- Construction stormwater runoff control
- Pollution prevention and good housekeeping practices for University Operations
- Total Maximum Daily Loads
- Huron River Watershed – (UM-Ann Arbor)
- Rouge River Watershed – (UM-Dearborn)
Click here to view the full plan.
Best management practices are an important tool in helping to protect storm runoff from the campus and ultimately, the Huron River. Below are a list of practices you can follow to assist with this important project.
- Deicing and Winter Maintenance
- Dye Testing
- Drainage System Maintenance
- Exterior Cleaning and Power Washing
- Facilities Planning and Design
- Flood Control
- Food Service Operations
- Fuel Dispensing and Vehicle Maintenance
- Household Hazardous Waste Disposal
- Landscaping Designs and Practices
- Pesticides, Herbicides and Fertilizers
- Preventing Spills
- Riparian Wetlands Protection
- Storm Drain Markers
- TMDL Practices - Phosphorus and E.coli
- Washing Vehicles
In 1995, the University of Michigan voluntarily applied for and was issued a Phase I NPDES MS4 Permit by the Michigan Department of Environmental Quality. Under this permit, the University created and implemented a SWMP, in compliance with the regulation. In 2001, the University renewed their NPDES Municipal Stormwater Permit MI0053902 and updated the SWMP. The University of Michigan is engaged in many activities aimed at eliminating stormwater pollution from campus operations. The Soil Erosion and Sedimentation Control Program and Stormwater Management Plan contain information on the University’s activities and programs.
Interested persons are invited to submit written comments on UM’s SWMPP via e-mail at email@example.com. Comments must include the following information:
- A statement of the person’s interest in the SWMPP;
- A statement of the action the person would like UM to take, including specific references to sections of the SWMPP that you believe should be changed; and
- The reasons supporting the person’s position, stated with sufficient specificity as to allow the UM to investigate the merits of the person’s position.
The Clean Water Act
Congress enacted the Clean Water Act (CWA) in 1972 in response to nationwide concern over water pollution and to protect sources of drinking water. The Act established national programs for the prevention, reduction, and elimination of pollution in national navigable waters and ground waters. It also set standards and introduced required permits for the discharge and treatment of wastewater from industries and municipalities. The CWA has brought about significant progress in cleaning up industrial wastewater and municipal sewage – specifically, single origins of pollution known as point sources.
With the reduction of point source pollution, it became evident that pollution from different sources over a wide, non-specific area, also known as non-point sources, was a major cause of water pollution. This is the type of pollution associated with Stormwater runoff. According to the Environmental Protection Agency, urban runoff is a major source of pollution for lakes and rivers. The 1987 Amendments to the CWA created provisions to address this issue.
The National Pollutant Discharge Elimination System (NPDES)
In an effort to reduce non-point source urban runoff pollution, the NPDES Stormwater Program was developed under the Federal Water Quality Act of 1987. Phase I of NPDES was introduced in 1990, targeting facilities determined most likely to impact water quality. This program made it necessary for these facilities to obtain permit coverage under NPDES for stormwater discharges. Phase I covers discharges from 10 industrial categories, construction activity disturbing 5 or more acres, and municipal separate storm sewer systems (MS4s), serving a population of at least 100,000. The Phase II rule was introduced in 1999. This program increased the number of facilities affected by the Stormwater Program. Under Phase II, MS4s serving a population of less than 100,000 and small construction sites, disturbing between 1 and 5 acres, are required to obtain permit coverage for stormwater discharges.
In addition to the Phase I and II permitting requirement, NPDES also specifies monitoring and reporting requirements. Under the municipal Stormwater program, each permittee is required to develop and implement a Stormwater Management Program (SWMP), a set of plans and procedures intended to reduce pollutants to the “maximum extent practicable.” With the SWMP, a permittee is required to:
- Identify system outfalls and pollutant loadings
- Detect and eliminate non-stormwater discharges
- Reduce runoff pollutants
- Control stormwater discharges from development and redevelopment areas
- Public education, outreach, and participation
- Illicit discharge detection and elimination
- Construction site runoff control
- Post-construction runoff control
- Pollution prevention/good housekeeping measures
The University issues annual and semi-annual reports describing the status of compliance with permit conditions associated with the stormwater management program. To view these reports, please follow the links below:
Annual Municipal Stormwater Discharge Reports (Fiscal Year)
Semi-Annual Municipal Stormwater Discharge Reports
U-M Non-Point Source Partner Reports
|2011||Summer 2010||Fall 2009||Summer 2009||Fall 2008|
|Spring 2008||Fall 2007||Spring 2007||Fall 2006||Spring 2006|
Since stormwater management is a relatively new field, researchers across the world are actively working to invent and improve structural stormwater BMP designs and treatment practices. With new findings, BMP designs are constantly evolving to increase pollutant removal and to further protect our waterways. Below is a list of well-established BMPs utilized by the University of Michigan to treat stormwater runoff.
Bioretention (i.e. Rain Gardens)
Bioretention systems are depressed areas that capture and treat runoff. Most often bioretention includes a gravel layer surrounding an underdrain, a sandy media mix layer atop the gravel to encourage infiltration, vegetation to further increase infiltration and pollutant removal, and a mulch layer to keep in moisture and to prevent internal erosion. Space is left between the underdrain and the bottom of the bioretention basin to promote further storage and thus infiltration.
Figure 1. Profile view of a typical bioretention/rain garden cell
There are several bioretention systems on campus. A great example is found right outside of the Dana Building on Central Campus. Next time you’re walking on campus be sure to check it out!
Constructed stormwater wetlands are designed to include several different water depth zones (shallow marsh zone, deep pool zone, etc.) that allows for the planting of many different wetland species. The carefully selected wetland vegetation aids in the capture and treatment of stormwater runoff. An example of a constructed wetland can be seen on North Campus near the Art and Architecture Building. The southern-most portion of this designed stormwater BMP system is a constructed wetland basin.
Figure 2. The constructed wetland basin included as part of the Art & Architecture stormwater management system
Dry/Wet Detention and Retention Basins
Dry detention basins are basins that remain predominantly dry between storm events. Stormwater runoff is captured during a storm event and is slowly released from the basin to make room for the next storm event. A wet detention basin is very similar, except some of the captured water always stays in the basin, even between storm events.
Dry and wet retention basins are very much like dry and wet detention basins. The only difference is retention basins are not designed to slowly release captured water- all water infiltrates.
There are numerous wet and dry retention and detention systems across campus…. next time you’re passing by the North Campus Grounds Services Building, be sure to look for the retention basin to the southeast of the building, and next time you’re out golfing, be sure to look for the large wet detention basin on the University Golf Course.
Figure 3. Wet detention basin at the University of Michigan Golf Course
Grassed Swales/Vegetated Swales
Grassed or vegetated swales are engineered ditches that promote infiltration while conveying stormwater runoff. These systems can be very simple ditches or very complex vegetated systems. A more complex vegetated swale that contains rock check-dam structures can be seen at the University of Michigan Arboretum (shown below).
Figure 4. Vegetated swale with built in check-dam structures located at the University of Michigan Arboretum
Green roofs are engineered systems that incorporate special media and vegetation to maximize infiltration and evapotranspiration on rooftops. If a building is not specifically designed to include a green roof, it is absolutely critical to confirm that the added weight of a green roof will not impact the structural stability of the building.
Most often, a green roof consists of an impermeable layer over a rooftop (to prevent leaks and structural damage), a drainage layer, a growing media layer, and a vegetation layer. The vegetation must be carefully selected for the local climate and must be able to endure various temperature extremes. Also, when selecting plants, remember that irrigation is discouraged and fertilization is a big no-no! Fertilizers, on or near a BMP, defeat the whole purpose of having the BMP.
Two common green roof types are intensive and extensive green roofs. Intensive green roofs are very intense systems- they have deep growing media for plant growth, large plant types (sometimes trees!) and may even support walking or sitting areas for people. Extensive green roofs have smaller growth media depths, smaller plant species and are generally not built for people to walk on. There are several green roof systems on campus- next time you walk by the Ross Business School or the Kresge Business Library look up and try to find one! Also, be on the lookout for the green roof covering the Mott Children’s Hospital and Von Voigtlander Women’s Hospital.
Figure 5. The green roof installed on top of the Mott Children’s Hospital and Von Voigtlander Women’s Hospital
Hydrodynamic Separators/Swirl Concentrators
Hydrodynamic separators and Swirl Concentrators are manufactured devices designed to remove sediment and/or oil and grease. These devices are often small in size and may be installed underground making them favorable in urban areas where space is limited and larger BMPs are not feasible. Unfortunately, most hydrodynamic separators and swirl concentrators are not suitable for removing nutrients from stormwater runoff, yet when properly designed and maintained they are very effective at removing sediment. Thus, hydrodynamic separators are great for pre-treatment; they are often placed upstream of larger underground or above ground BMPs to prevent the downstream BMP from clogging with sediment. Hydrodynamic separators lower maintenance costs associated with sediment removal and often improve the function of downstream BMPs.
Example: A hydrodynamic device can be placed upstream of a detention basin to reduce the sediment load that enters the detention basin. Essentially the separator is acting as a forebay and is protecting the basin from sediment deposition.
Hydrodynamic separators are used all across campus but may be difficult to see since most are underground!
Figure 6. The manhole cover to an underground hydrodynamic device
Infiltration Devices (Sand filters, Planter Boxes, etc)
Infiltration devices are very similar to bioretention in that they encourage the infiltration of runoff through a media. There are numerous types of infiltration devices with various media types and vegetation types (or no vegetation at all in some cases). Most often sand filters are underground devices that do not include vegetation; whereas, infiltration planter boxes are above-ground planters that incorporate an infiltration/ growth media and vegetation. See if you can spot two infiltration planter boxes outside of the Ross Business School next time you’re on Central Campus!
Level Spreader-Vegetated Filter Strips
Most often level spreaders are long, thin, very evenly laid strips of concrete that receive flow and evenly distribute the flow to a downstream vegetated area. Level spreaders must be very flat in order to be effective, otherwise flow will accumulate in one area and cause erosion. When properly installed, level spreaders evenly disperse flow and greatly improve infiltration.
Figure 7. Profile of a Level Spreader - Vegetated Filter Strip System
There are all sorts of design alternatives to traditional pavement, including: permeable pavement, permeable asphalt, permeable pavers, and permeable concrete and unlike traditional pavement, all of these systems allow for the infiltration of stormwater runoff! Most often a top layer of coarse material (permeable concrete, asphalt, or pavers) is laid over top of a crushed stone mix to allow for maximum infiltration of stormwater runoff. The primary type of pavement is selected depending on the ultimate use, for example, permeable asphalt and concrete types are often used on roadways or in parking lots, whereas permeable pavers are more commonly seen in pedestrian areas or short term parking lots.
While under-drains are commonly installed to ensure adequate drainage, permeable pavement systems are most effective in areas with good draining in-situ soils (i.e.sandy soils)
There are several permeable pavement systems on campus including permeable asphalt, permeable pavement, and permeable pavers.
Figure 8. Examples of porous pavement (left) and permeable pavers (right) used on campus
Underground detention systems are manufactured units designed to capture and hold stormwater runoff. Captured water is allowed to infiltrate into existing soils and slowly release over time. Such devices have been shown to remove nutrients, sediment, and reduce the temperature of water (which is great for trout sensitive waters!) There are plenty of underground detention structures across campus; however, much like the hydrodynamic devices, these systems will be hard to find as they are underground! For example, every time you play soccer at Palmer field, you’re running on-top of an underground detention system!
Structural Stormwater BMP Resources
If you would like further information on BMPs, including: information on design, pollutant removal, regulatory requirements, or current research there are a ton of excellent sources! Below are just a few resources to learn more.
In Ann Arbor, there are two types of systems that handle sewage and stormwater: sanitary sewers and stormwater drainage systems. A sanitary sewer system is designed to transport wastewater from homes, offices, restaurants, and shops to the wastewater treatment plant (WWTP), where it is treated before being discharged to surface water bodies. Stormwater drainage systems are designed to transport surface runoff from rainstorms and snowmelts into lakes, rivers, streams, and ponds. Water that enters the stormwater drainage system is not treated before being discharged into surface waters.
The City of Ann Arbor and the University of Michigan use both a sanitary sewer and a stormwater drainage system.
The City of Ann Arbor Sanitary Sewer System & Wastewater Treatment Plant
The Ann Arbor WWTP receives its input from the City's sanitary sewer system. The sanitary sewer collects wastewater from residential, commercial, industrial, and campus facilities. Wastewater that reaches the Ann Arbor WWTP through the sanitary sewer is treated in a number of ways before being discharged to the Huron River. Dirt and debris, bacteria, organic material, and nutrients that have potential to cause adverse environmental and human health effects are all removed from wastewater before it is released from the plant.
The citizens of Ann Arbor rely on the WWTP to help maintain the integrity of the Huron River. The WWTP analyzes the influent and effluent of the plant daily, to ensure the effectiveness of its treatment processes and their compliance with federal and state regulations. The following links offer more information regarding the WWTP and its operations:
Environmental problems evolve slowly and tend to sneak up on us with damage usually being done before we realize anything is wrong. It is hard for us to imagine that a drip of oil or a bit of dirt will harm our water supply, but even small amounts can pollute a vast amount of water. One quart of oil can contaminate up to 2 million gallons of water. Tasks you perform daily may have a potential impact on what is washed down the storm drain. Here are some things to watch for and incorporate into everyday assignments or procedures. Two excellent sources of information developed by U-M OSEH include: Improving Surface Water Quality on Campus and Improving Surface Water Quality at Home.
Knowing the relationship between the nearest storm drains and your living and working areas makes it easier to take precautions to prevent materials from entering them. Whenever necessary, the drains should be plugged or bermed to prevent contaminated liquids from entering the storm system. Even if your activity doesn't require water, it is a good idea to cover the storm drain to prevent any loose material from getting into the system. Sweep the area and pick up the debris instead of washing it down the drain. If sediment is a concern, fabric bag filters can be hung in the catch basin to filter solids from runoff. These bags can be removed when they are full. If possible, divert any water to a vegetated area after all, the grass can really use the water.
Dumpsters are a common source of pollutants, especially when they contain damp or oily wastes. NEVER PLACE LIQUIDS INTO A DUMPSTER. Placing dumpters on concrete surfaces and keeping their lids tightly closed to keep out the rain can minimize leaking. If possible, build a shelter over them. If a dumpster leaks, immediately repair or replace it. Post signs to remind others to dispose of waste properly. Routinely clean up debris and litter in outside areas and pay special attention to parking lots, loading docks, waste storage areas and drain inlets. Assign someone to regularly pick up litter and sweep up any loose material before it has a chance to make its way to the storm drain.
Clean field equipment and vehicles with as little water as possible or wash the vehicle on the grass. For example, remove dirt and grit using wire brushes or other dry methods before applying solvent or water. Be sure to collect the dislodged material and dispose in the trash.
Taking a few simple precautions to prevent a spill will eliminate the headaches that come with cleaning up after one! Remain in attendance when tanks and open containers are being filled. Use secondary containers whenever carrying materials from one location to another. Use a funnel when transferring liquids from one container to another. Place trays under open containers and the spouts of liquid storage containers.
If improper dumping or discharge is observed on University property, immediately notify the University's Department of Occupational Safety and Environmental Health (OSEH) at 7-1143 or the University's Department of Public Safety (DPS) at 3-1131. Report any off-campus dumping into Ann Arbor storm drains to the City of Ann Arbor Water Utilities Department at 994-1760.
Training for Staff
Because many of the activities that protect water quality need to be performed continuously, employee education is key to any successful pollution prevention initiative. Staff education activities should include:
- Train employees to routinely inspect equipment and activities for opportunities to prevent pollution.
- Make water quality protection part of new employee training by assigning experienced workers to train new ones.
- Conduct a routine walk-through of work areas to identify potential problems.
- Encourage staff participation in protecting water quality by providing incentives.
- Review procedures once a year with employees. Incorporate this training with "worker right-to-know" training for hazardous materials or worker safety training programs.
- Display signs describing water quality protection activities where employees and visitors will see them.
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