Stormwater
Stormwater, also written storm water, is
) without treatment.In natural landscapes, such as forests, soil absorbs much of the stormwater. Plants also reduce stormwater by improving infiltration, intercepting precipitation as it falls, and by taking up water through their roots. In developed environments, such as
Stormwater is also an important resource as human population and demand for water grow, particularly in arid and drought-prone climates. Stormwater harvesting techniques and purification could potentially make some urban environments self-sustaining in terms of water.
Impacts of stormwater
Stormwater pollution
With less vegetation and more
A first flush is the initial runoff of a rainstorm. During this phase, polluted water entering storm drains in areas with high proportions of impervious surfaces is typically more concentrated compared to the remainder of the storm. Consequently, these high concentrations of urban runoff result in high levels of pollutants discharged from storm sewers to surface waters.[2][3]: 216
Daily human activities result in deposition of pollutants on roads, lawns, roofs, farm fields, and other land surfaces. Such pollutants include trash, sediment, nutrients, bacteria, pesticides, metals, and petroleum byproducts.[4] When it rains or there is irrigation, water runs off and ultimately makes its way to a river, lake, or the ocean. While there is some attenuation of these pollutants before entering receiving waters, polluted runoff results in large enough quantities of pollutants to impair receiving waters.[5]
Stormwater runoff as a source of pollution
In addition to the pollutants carried in stormwater runoff, urban runoff is being recognized as a cause of pollution in its own right. In natural catchments (watersheds) surface runoff entering waterways is a relatively rare event, occurring only a few times each year and generally after larger storms. Before development occurred, most rainfall soaked into the ground and contributed to groundwater recharge or was recycled into the atmosphere by vegetation through evapotranspiration.
Modern drainage systems, which collect runoff from impervious surfaces (e.g., roofs and roads), ensure that water is efficiently moved to waterways through pipe networks, meaning that even small storms result in increased waterway flows.
In addition to delivering higher pollutants from the urban catchment, increased stormwater flow can lead to stream erosion, encourage weed invasion, and alter natural flow regimes. Native species often rely on such flow regimes for spawning, juvenile development, and migration. Stormwater runoff from roadways has been observed to contain many metals including zinc (Zn), cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb), chromium (Cr), manganese (Mn), iron (Fe), vanadium (V), cobalt (Co), and aluminum (Al) (Sansalone and Buchberger, 1997; Westerlund and Viklander, 2006)[full citation needed] and other constituents.
In some areas, especially along the U.S. coast, polluted runoff from roads and highways may be the largest source of water pollution. For example, about 75 percent of the toxic chemicals getting to Seattle, Washington's Puget Sound are carried by stormwater that runs off paved roads and driveways, rooftops, yards, and other developed land.[6]
Industrial stormwater is runoff from precipitation that lands on industrial sites (e.g. manufacturing facilities, mines, airports). This runoff is often polluted by materials that are handled or stored on the sites, and the facilities are subject to regulations to control the discharges.[7][8]
Urban flooding
Stormwater is a major cause of
Where properties are built with
Stormwater creation of sinkhole collapses
An example of urban stormwater creating a sinkhole collapse is the February 25, 2002 Dishman Lane collapse in Bowling Green, Kentucky where a sinkhole suddenly dropped the road under four traveling vehicles. The nine-month repair of the Dishman Lane collapse cost a million dollars but there remains the potential for future problems.[11]
In undisturbed areas with natural subsurface (karst) drainage, soil and rock fragments choke karst openings thereby being a self-limitation to the growth of openings.[12]: 189–190, 196 The undisturbed karst drainage system becomes balanced with the climate so it can drain the water produced by most storms. However, problems occur when the landscape is altered by urban development.[13]: 28 In urban areas with natural subsurface (karst) drainage there are no surface streams for the increased stormwater from impervious surfaces such as roofs, parking lots, and streets to runoff into. Instead, the stormwater enters the subsurface drainage system by moving down through the ground. When the subsurface water flow becomes great enough to transport soil and rock fragments, the karst openings grow rapidly.[12]: 190 Where karst openings are roofed by supportive (competent) limestone, there frequently is no surface warning that an opening has grown so large it will suddenly collapse catastrophically.[12]: 198 Therefore, land use planning for new development needs to avoid karst areas.[13]: 37–38 Ultimately taxpayers end up paying the costs for poor land use decisions.
Stormwater management
Managing the quantity and quality of stormwater is termed, "Stormwater Management."
Technical aspects
This section is in prose. is available. (March 2023) |
- control of flooding and erosion;
- control of hazardous materials to prevent release of pollutants into the environment (source control);
- planning and construction of stormwater systems like retention basins, buried vaults with various kinds of media filters, and vortex separators to remove coarse solids[17] before they pollute surface waters or groundwater resources;
- acquisition and protection of natural waterways or rehabilitation;
- building constructed wetlands or green infrastructuresolutions to work with existing or "hard" drainage structures, such as pipes and concrete channels (constructed wetlands built for stormwater treatment can also serve as habitat for plants, amphibians and fish)
Institutional and policy aspects
This section is in prose. is available. (March 2023) |
- development of funding approaches to stormwater programs potentially including stormwater user fees and the creation of a stormwater utility;
- development of long-term asset management programs to repair and replace aging infrastructure;
- revision of current stormwater regulations to address comprehensive stormwater needs;
- enhancement and enforcement of existing ordinances to make sure property owners consider the effects of stormwater before, during and after development of their land;
- education of a community about how its actions affect water quality, and about what it can do to improve water quality.
Integrated water management
Integrated water management (IWM) of stormwater has the potential to address many of the issues affecting the health of waterways and water supply challenges facing the modern urban city. IWM is often associated with
Also known as
, IWM has the potential to improve runoff quality, reduce the risk and impact of flooding and deliver an additional water resource to augment potable supply.The development of the modern city often results in increased demands for water supply due to population growth, while at the same time altered runoff predicted by climate change has the potential to increase the volume of stormwater that can contribute to drainage and flooding problems. IWM offers several techniques, including stormwater harvest (to reduce the amount of water that can cause flooding),
There are many ways of achieving LID. The most popular is to incorporate land-based solutions to reduce stormwater runoff through the use of retention ponds, bioswales, infiltration trenches, sustainable pavements (such as permeable paving), and others noted above. LID can also be achieved by utilizing engineered, manufactured products to achieve similar, or potentially better, results as land-based systems (underground storage tanks, stormwater treatment systems, biofilters, etc.). The proper LID solution is one that balances the desired results (controlling runoff and pollution) with the associated costs (loss of usable land for land-based systems versus capital cost of manufactured solution). Green (vegetated) roofs are also another low-cost solution.
IWM as a movement can be regarded as being in its infancy and brings together elements of drainage science, ecology and a realization that traditional drainage solutions transfer problems further downstream to the detriment of the environment and water resources.
Regulations
United States
Federal requirements
In the
To address the nationwide problem of stormwater pollution,
State and local requirements
EPA has authorized 47 states to issue NPDES permits.[24] In addition to implementing the NPDES requirements, many states and local governments have enacted their own stormwater management laws and ordinances, and some have published stormwater treatment design manuals.[14][25] Some of these state and local requirements have expanded coverage beyond the federal requirements. For example, the State of Maryland requires erosion and sediment controls on construction sites of 5,000 sq ft (460 m2) or more.[26] It is not uncommon for state agencies to revise their requirements and impose them upon counties and cities; daily fines ranging as high as $25,000 can be imposed for failure to modify their local stormwater permitting for construction sites, for instance.
Nonpoint source pollution management
Agricultural runoff (except for concentrated animal feeding operations, or "
Public education campaigns
Education is a key component of stormwater management. A number of agencies and organizations have launched campaigns to teach the public about stormwater pollution, and how they can contribute to solving it. Thousands of local governments in the U.S. have developed education programs as required by their NPDES stormwater permits.[29]
One example of a local educational program is that of the West Michigan Environmental Action Council (WMEAC), which has coined the term Hydrofilth to describe stormwater pollution,
Other public education campaigns highlight the importance of green infrastructure in slowing down and treating stormwater runoff. DuPage County Stormwater Management launched the "Love Blue. Live Green." outreach campaign on social media sites to educate the public on green infrastructure and some other best management practices for stormwater runoff.[33] Articles, websites, pictures, videos and other media are spread to the public through this campaign.
History
Stormwater infrastructure is an expensive long-term investment that is difficult to replace when the underlying circumstances change. As a result, the system will perform worse or malfunction more frequently over time. This is precisely what is occurring in the region surrounding Europe and the Baltic Sea, where the systems are being stressed by the quickening pace of climate change, the advancement of urbanization, and the stricter regulations. Rethinking stormwater management techniques and stepping up investments in stormwater infrastructure are essential to adapting to these rapidly changing circumstances.[34][35]
Since humans began living in concentrated village or urban settings, stormwater runoff has been an issue. During the Bronze Age, housing took a more concentrated form, and impervious surfaces emerged as a factor in the design of early human settlements. Some of the early incorporation of stormwater engineering is evidenced in Ancient Greece.[36]
A specific example of an early stormwater runoff system design is found in the
See also
- Nationwide Urban Runoff Program (U.S. research program)
- Sanitary sewer overflow
- Stochastic Empirical Loading and Dilution Model
References
- ^ Schueler, Thomas R. "The Importance of Imperviousness." Archived 2014-03-27 at the Wayback Machine Reprinted in The Practice of Watershed Protection. 2000. Center for Watershed Protection, Ellicott City, MD.
- ^ Metcalf, Leonard; Eddy, Harrison P. (1916). American Sewerage Practice: Disposal of Sewage. Vol. III. New York: McGraw-Hill. p. 154.
- ^ Alex Maestre and Robert Pitt; Center for Watershed Protection (2005)."The National Stormwater Quality Database, Version 1.1: A Compilation and Analysis of NPDES Stormwater Monitoring Information." Report prepared for U.S. Environmental Protection Agency (EPA), Washington, DC. September 4, 2005.
- ^ "Runoff: Surface and Overland Water Runoff". www.usgs.gov. Retrieved 2019-08-15.
- ^ U.S. Environmental Protection Agency, Washington, DC. "Results of the Nationwide Urban Runoff Program: Volume 1 – Final Report", Water Planning Division. 1983.
- ^ Washington State Department of Ecology. "Control of Toxic Chemicals in Puget Sound, Phase 2: Development of Simple Numerical Models" Archived 2017-03-02 at the Wayback Machine, 2008
- PMID 31905584.
- ^ "Stormwater Discharges from Industrial Activities". EPA. 2022-11-28.
- ^ Indoor Air Quality (IAQ) Scientific Findings Resource Bank (IAQ-SFRB), "Health Risks or Dampness or Mold in Houses" "Indoor Air Quality Scientific Findings Resource Bank : Indoor Dampness, Biological Contaminants and Health : Health Risk of Dampness or Mold in Houses". Archived from the original on 2013-10-04. Retrieved 2013-09-17.
- ^ hermesauto (2016-09-06). "Plastic bags clogging Bangkok's sewers complicate efforts to fight floods". The Straits Times. Retrieved 2020-11-17.
- ^ Kambesis, P., R. Brucker, T. Waltham, F. Bell, and M. Culshaw. "Collapse sinkhole at Dishman Lane, Kentucky." Sinkholes and Subsidence: Karst and Cavernous Rocks in Engineering and Construction. Springer, Berlin (2005): 277-282.
- ^ a b c Palmer, Arthur N."Groundwater processes in karst terranes." Ground water geomorphology (1990): 177-209.
- ^ a b Veni, George. Living with Karst. American Geological Institute, 2001.
- ^ a b Washington State Department of Ecology (2005). Olympia, WA. "Stormwater Management Manual for Western Washington." Archived 2012-04-02 at the Wayback Machine Publication No. 05-10-029.
- ISBN 978-0-309-12540-6.
- ISBN 1-56670-584-3.
- ISBN 978-0-87371-924-7.
- ^ Prince George's County, Maryland. Department of Environmental Resources (January 2000). Low-Impact Development Design Strategies, An Integrated Design Approach (Report). EPA. EPA 841-B-00-003.
- ^ "Water Sensitive Urban Design - Melbourne Water". Wsud.melbournewater.com.au. Retrieved 2011-12-05.
- Pub. L.92–500, October 18, 1972.
- ^ National Water Quality Inventory: Report to Congress; 2004 Reporting Cycle (Report). EPA. January 2009. EPA 841-R-08-001.
- .
- ^ "Overview". NPDES / Stormwater Discharges from Municipal Sources. EPA. 2017-07-21.
- ^ "NPDES State Program Information". National Pollutant Discharge Elimination System. EPA. 2018-08-20.
- ^ Maryland Stormwater Design Manual (Report). Baltimore, MD: Maryland Department of the Environment. 2009. Archived from the original on 2016-02-07.
- ^ State of Maryland. Code of Maryland Regulations (COMAR). Activities for Which Approved Erosion and Sediment Control Plans are Required. Sec. 26.17.01.05.
- ^ Clean Water Act sec. 319, 33 U.S.C. § 1329.
- ^ "Environmental Quality Incentives Program". Washington, D.C.: U.S. Natural Resources Conservation Service. 2023-03-27.
- ^ "Developing an MS4 Program". NPDES/Stormwater Discharges from Municipal Sources. EPA. 2016.
- ^ West Michigan Environmental Action Council (WMEAC), Grand Rapids, MI. "Stop Hydrofilth." Accessed 2013-08-26.
- ^ WMEAC. "15 to the River" Accessed 2013-08-26.
- ^ WMEAC. "Rain Gardens... beautiful solutions for water pollution." Accessed 2013-08-26.
- ^ DuPage County Stormwater Management. "Education and Outreach." Accessed 2013-12-27.
- doi:10.3390/w15081623. This article incorporates text from this source, which is by Ivar Annus, Nils Kändler, Tobias Karlsson, Antonius Van Maris, Antti Kaseva, Nika Kotoviča, and Gunaratna Kuttuva Rajarao available under the CC BY 4.0license.
- ^ Le, J. T., Gonzalez, J. P., Carson, R. T., Ambrose, R. F., & Levin, L. A. (2023). Integrating non-targeted ecosystem services into assessment of natural stormwater treatment systems. Water, 15(8), 1460. https://doi.org/10.3390/w15081460
- ISBN 978-0-8493-9627-4.
- ^ C. Michael Hogan, "Phaistos Fieldnotes." The Modern Antiquarian (2007).
External links
- Stormwater at Curlie
- EPA Stormwater Permit Program
- Stormwater Model USGS Stochastic Empirical Loading and Dilution Model(SELDM)
- Stormwater Model USEPA Storm Water Management Model (SWMM)
- International Stormwater Best Management Practices (BMP) Database
- Stormwater YouTube Page