Resources by David J Sample
|Urban Stormwater: Terms and Definitions||Sep 5, 2013||426-119 (BSE-78P)|
|Best Management Practice Fact Sheet 1: Rooftop Disconnection||Sep 5, 2013||426-120 (BSE-93P)|
|Best Management Practice Fact Sheet 2: Sheet Flow to Open Space||
Sheet flow to open space (SOS) is a group of best management practices (BMPs) designed to disperse concentrated runoff to sheet flow into filter strips or a riparian buffer. An SOS reduces runoff volume and associated sediment and nutrients that are carried with it (see figure 1). It is used as a stormwater treatment practice in both urban and rural areas. This practice is often used after another treatment practice to disperse or eliminate runoff. In a few cases, an SOS can be used as a pretreatment to remove small amounts of sediment via a vegetated filter strip — prior to a bioretention device, for example.
|Sep 6, 2013||426-121 (BSE-83P)|
|Best Management Practice Fact Sheet 3: Grass Channels||Sep 6, 2013||426-122 (BSE-88P)|
|Best Management Practice Fact Sheet 4: Soil Restoration||
Soil restoration (SR) is the technique of enhancing compacted soils to improve their porosity and nutrient retention. It includes biological (worms) and mechanical aeration, mechanical loosening (tilling), planting dense vegetation, and applying soil amendments. Soil amendments involve the spreading and mixing of mature compost into disturbed and compacted urban soils (see Figure 1).
|Sep 6, 2013||426-123 (BSE-80P)|
|Best Management Practice Fact Sheet 5: Vegetated Roofs||
A vegetated roof (VR) is a best management practice (BMP) that reduces stormwater runoff and pollution. Vegetation and media create a permeable system on a previously impervious surface. The VR intercepts rainfall and filters runoff while reducing the volume and velocity. Vegetated roofs consist of a waterproofing barrier, drainage system, and engineered growing media. There are two types of VRs: intensive and extensive. Intensive vegetated roofs are deeper and heavier, while extensive vegetated roofs are shallower, lighter, and more common (see Figure 1). The type of VR determines the amount of maintenance necessary to maintain the vegetation.
|Sep 6, 2013||426-124 (BSE-81P)|
|Best Management Practice Fact Sheet 6: Rainwater Harvesting||
Rainwater harvesting (RWH), also known as rainwater harvesting systems or cisterns, are devices that intercept, divert, store, and release collected roof runoff from rainfall for later use as an alternative water supply (see figure 1). RWH can also be designed to provide runoff reduction benefits. Therefore, it is classified as a best management practice (BMP) for treatment of urban stormwater. Because of its dual purpose and benefit, RWH is often classified as a sustainable urban BMP.
|Sep 6, 2013||426-125 (BSE-90P)|
|Best Management Practice Fact Sheet 7: Permeable Pavement||
Permeable pavement (PP) is a modified form of asphalt or concrete with a top layer that is pervious to water due to voids intentionally created during mixing. PPs include pervious concrete, porous asphalt, and interlocking concrete pavers. These materials are used as stormwater treatment practices in urban areas. They are used in place of traditionally impervious surfaces to allow infiltration and storage, thus reducing runoff (see figure 1).
|Sep 6, 2013||426-126 (BSE-84P)|
|Best Management Practice Fact Sheet 8: Infiltration Practices||
Infiltration practices provide temporary surface and/or subsurface storage, allowing infiltration of runoff into soils. In practice, an excavated trench is usually filled with gravel or stone media, where runoff is stored in pore spaces or voids between the stones (see figure 1). These systems can reduce significant quantities of stormwater by enhancing infiltration, as well as provide filtering and adsorption of pollutants within the stone media and soils. Infiltration practices are part of a group of stormwater treatment practices, also known as best management practices (BMPs)
|Mar 2, 2012||426-127 (BSE-85P)|
|Best Management Practice Fact Sheet 9: Bioretention||
A bioretention cell, or rain garden, is a best management practice (BMP) designed to treat stormwater runoff from roofs, driveways, walkways, or lawns. They are a shallow, landscaped depression that receives and treats polluted stormwater with the goal of discharging water of a quality and quantity similar to that of a forested watershed (figure 1).
|Sep 6, 2013||426-128(BSE-92P)|
|Best Management Practice Fact Sheet 10: Dry Swale||
A dry swale (DS) is a shallow, gently sloping channel with broad, vegetated, side slopes. Water flow is slowed by a series of check dams (see figure 1). A DS provides temporary storage, filtration, and infiltration of stormwater runoff. Dry swales function similarly to bioretention, and are comparable to wet swales; however, unlike a wet swale, a DS should remain dry during periods of no rainfall. A DS is an engineered best management practice (BMP) that is designed to reduce pollution through runoff reduction and pollutant removal and is part of a site’s stormwater treatment practice (see figure 2).
|Sep 6, 2013||426-129 (BSE-86P)|
|Best Management Practice Fact Sheet 11: Wet Swale||
A wet swale (WS) is an engineered, best management practice (BMP) arranged in a straight line that is designed to reduce stormwater pollution. A WS consists of a shallow, gently sloping channel with broad, vegetated, side slopes and slow flows (see figure 1). Wet swales typically stay wet because the bottom of the swale is below the water table. This is done to encourage the growth of wetland vegetation, providing water quality treatment similar to a natural wetland. This stormwater treatment practice also functions as part of the stormwater conveyance system. Wet swales have a relatively low capital cost; however, maintenance can be is intensive and expensive when compared to other BMPs.
|Sep 9, 2013||426-130 (BSE-89P)|
|Best Management Practice Fact Sheet 12: Filtering Practices||
A stormwater filtering practice (FP) treats stormwater runoff by passing it through an engineered filter media consisting of either sand, gravel, organic matter, and/ or a proprietary manufactured product, collecting it in an underdrain, and then discharging the effluent to a stormwater conveyance system. FPs are stormwater treatment practices that are often obtained from the marketplace due to unique proprietary technologies (see figure 1).
|Sep 9, 2013||426-131 (BSE-87P)|
|Best Management Practice Fact Sheet 13: Constructed Wetlands||
A constructed wetland (CW) is a low-cost and sustainable, engineered, best management practice (BMP) designed to reduce stormwater pollution. Constructed wetlands are considered to be one of the most reliable stormwater treatment practices. They are designed to function similarly to a self-sustaining natural wetland, and should require only moderate maintenance to function (figure 1).
|Sep 9, 2013||426-132 (BSE-91P)|
|Best Management Practice Fact Sheet 14: Wet Ponds||
Wet ponds (WP) are ponds or lakes which provide treatment and storage of stormwater. The water depth is set by a structure known as an outlet structure. Wet ponds are probably the most well-known best management practice for treatment of stormwater. Because of their size, they are usually designed to include storage above the normal pool elevation. This added storage can provide reductions in downstream flooding and assist in protecting stream channels. They tend to be large; in some cases, they can become a passive community amenity (See Figure 1).
|Sep 9, 2013||426-133 (BSE-79P)|
|Best Management Practice Fact Sheet 15: Extended Detention Ponds||
Extended detention ponds (EDs) are dry detention ponds that provide 12 to 24 hours of runoff storage during peak runoff events (see figure 1). Releases from the ED ponds are controlled by an outlet structure. During a storm event, as the discharge restriction is reached, water backs up into the ED pond. The pool slows flow velocities and enables particulate pollutants to settle. Peak flows are also reduced. ED ponds have the lowest overall pollutant- removal rate of any stormwater treatment option, so they are often combined with other upstream, lowimpact development (LID) practices to better maximize pollutant-removal rates. Due to their placement at the exit point of the watershed, ED is often the last opportunity to treat stormwater before it is discharged to a stream. Because of its low treatment performance, an ED should be viewed as the treatment option of last resort.
|Sep 9, 2013||426-134 (BSE-82P)|
|Understanding Soil Moisture Sensors: A Fact Sheet for Irrigation Professionals in Virginia||
In the Commonwealth of Virginia, water resources are increasingly being scrutinized due to changing surface water or groundwater availability. Access to good quality water is a continuing concern, and in many communities, managing water use — particularly consumptive use — is a priority to conserve public water supplies to meet the needs of a growing population.
|Sep 23, 2016||BSE-198P|
|Innovative Best Management Fact Sheet No. 1: Floating Treatment Wetlands||Aug 28, 2013||BSE-76P|
|Decentralized Small Community Wastewater Collection Systems||
Wastewater is a significant source of carbon, sediment, nutrients, pathogens, and other potential pollutants. Reducing the quantity of these contaminants before they are discharged to either groundwater or surface water is essential to preserve or enhance water quality in receiving waters. This is accomplished through the installation of wastewater treatment and collection systems. The form of these systems can vary substantially. In Virginia, they range in size from 5,000 to 50,000 gallons per day; 49 percent are public systems and the remainder are private (Parten 2008).
|Jul 10, 2014||BSE-77P|