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Montgomery County Department of Park and Planning The Kemp Mill Master Plan environmental study area encompasses 1,900 acres in southeastern Montgomery County, approximately two miles north of the District of Columbia line. The Kemp Mill study area is densely populated with residential neighborhoods flanked by large areas of forested parkland. The Kemp Mill study area is bounded on the east by the Northwest Branch Stream Valley Park; on the south by Dennis Avenue, University Boulevard and Eisner Street; on the west by Sligo Creek Stream Valley Park and Wheaton Regional Park; and on the north by Randolph Road (see Figure 1). Portions of these parks lie within the study area. The Kemp Mill study area lies within the Piedmont geological province. The Piedmont province is characterized by resistant, metamorphic rock made up of gneiss, granite and schist. Metamorphic rocks are associated with the formation of mountain ranges and are typically found in upland areas. Schist is the primary metamorphic rock found within the study area. The subsurface condition of the Piedmont province supports a wide range of natural features and is generally conducive to development. The dominant soil type in the Kemp Mill study area is a combination of the Urban and Glenelg series. Urban "soil" consists of areas where the original soil has been disturbed and large areas have been covered by concrete, asphalt and buildings, while the Glenelg series consists of deep, well-drained soils. Other soils found within the study area include the Hatboro series which are associated with floodplains, the Baile series commonly found along drainage-ways and the Blocktown series found on uplands (see Figure 2). Elevation in the study area ranges from 230' to 450'. Topography naturally tends to be steeper near stream valleys and more level in the upland and developed areas. The Maryland Planning Act of 1992 supports protection of sensitive environmental areas and stewardship of the lands of the Chesapeake Bay. Sensitive areas include streams and their buffers, 100-year floodplains, habitats of rare, threatened and endangered species, and steep slopes' Sensitive areas are protected from disturbance by development under the Guidelines for Environmental Management of Development in Montgomery County. All new commercial and subdivision development must comply with current county and state environmental requirements, including forest conservation, stormwater management, sediment control, and development restrictions within streams, wetlands and floodplains. Most of the sensitive areas located within the study area boundaries are found within the Northwest Branch Stream Valley Park, Sligo Creek Stream Valley Park and Wheaton Regional Park (see Figure 3). The Kemp Mill study area falls within two major watersheds of the Anacostia River: Northwest Branch and Sligo Creek. In 1998, the Montgomery County Department of Environmental Planning developed the County-wide Stream Protection Strategy (CSPS) to provide an overall assessment of County stream conditions in order to identify and prioritize the subwatershed areas most in need of protection. The CSPS divides the county into subwatersheds and classifies the subwatersheds within the Kemp Mill study area as Watershed Restoration Areas. A Watershed Restoration Area is a watershed with varying degrees of degradation (see Appendix A). According to the CSPS, stream conditions within the Kemp Mill study area's subwatersheds range from poor to fair (see Figure 4). These degraded conditions are due primarily to the effects of uncontrolled runoff from existing development built prior to the application of today's standards for environmental protection. The Kemp Mill study area has an overall level of imperviousness of 16.5 percent. Impervious surfaces, such as pavement, buildings and sidewalks, cannot be penetrated by water, thus prohibiting rainfall from infiltrating the ground. Instead, water runoff travels overland to streams and rivers, quickly increasing in temperature and collecting pollutants like oil, grease, and dirt. These pollutants are then deposited into the streams and can harm or kill aquatic life. Northwest Branch The Northwest Branch is the largest tributary to the Anacostia River. Originating near Route 108 in the Olney/Sandy Spring area, the Northwest Branch flows south to the Anacostia River mainstem in Prince George's County. The headwaters of the Northwest Branch drain portions of the less-developed Cleverly and Sandy Spring/Ashton master plan study areas and the southern part of the watershed drains the more intensely developed master plan study areas such as White Oak, Aspen Hill and Kemp Mill. The Northwest Branch watershed covers more than 19,600 acres, with approximately 1,500 acres encompassed by the Kemp Mill study area. The study area includes portions of five subwatersheds of the Northwest Branch: Lamberton Drive tributary, Lockridge Drive tributary, Middle Mainstem tributary, Middle Mainstem Glenmont tributary and Wheaton Park tributary (see Figure 5). The CSPS has determined that three subwatersheds, Lamberton Drive, Lockridge Drive and Middle Mainstem tributary, are priority subwatersheds based on the high levels of imperviousness, uncontrolled runoff and poor bank stability that they exhibit. Priority subwatersheds were identified by comparing the existing stream condition to the projected levels of imperviousness based on anticipated future development. In addition, all subwatersheds exhibiting high levels of channel instability were given priority status (see Figure 4). The following table shows the current levels of imperviousness by subwatershed.
Note: Portions of these subwatersheds extend beyond the Kemp Mill study area (see Figure 5). The state of Maryland classifies the Northwest Branch watershed as Use IV stream. A Use IV designation indicates that stream waters are capable of supporting adult trout for catch-and-release fishing. Therefore, the water quality protection criteria for Use IV is more stringent than criteria for most streams in urban areas that have a Use I classification. Species other than trout can also be found in the Northwest Branch, including rosyside dace, northern hogsuckers and five species of shiners. Although the same species can be found throughout the watershed, the aquatic community composition varies dramatically in response to habitat, water flow and pollutants. Sligo Creek The 5,510-acre Sligo Creek watershed originates in Wheaton and flows into the Northwest Branch in Prince George's County. Sligo Creek is one of the county's most developed watersheds, draining parts of Wheaton and Silver Spring Central Business Districts and Takoma Park. The Kemp Mill study area encompasses 420 acres of a single Sligo Creek subwatershed: Upper Sligo Creek (see Figure 5). Over the last ten years more than $2.5 million has been invested by federal, state and local government agencies to improve stormwater management, water quality and aquatic habitat of the Sligo Creek watershed. Restoration efforts directly affecting the Kemp Mill study area include the stormwater management facility north of University Boulevard and in-stream stabilization of Sligo Creek extending north of Dennis Avenue to University Boulevard. Other Sligo Creek watershed restoration projects include riparian planting, biological monitoring, reintroduction of native fish species, vernal pool creation and habitat creation. Prior to these improvements, the only fish identified in the Sligo Creek watershed were blacknose dace, goldfish and creek chub - species that are highly tolerant of polluted conditions. As of 1998, biological monitoring conducted by the Interstate Commission of the Potomac River Basin (ICPRB) indicated that the number of native fish species in the Upper Sligo Creek watershed increased from three to eleven. The Sligo Stream Valley Park Management Plan, developed by M-NCPPC, Department of Park and Planning in 1995, recommends improving Sligo Creek Stream Valley Park between University Boulevard and Dennis Avenue. Proposed improvements consist of continuing in-stream stabilization efforts, increasing tree, shrub and wetlands vegetation plantings, reconfiguring asphalt and gravel parking areas along Sligo Creek Parkway to provide more accessible parking, and finally, relocating play equipment and picnic tables currently located within the stream buffer. The level of imperviousness for the Upper Sligo Creek watershed is 26%, according to the CSPS. The state of Maryland classifies Sligo Creek watershed as Use 1. A Use I designation is defined as suitable for water contact sports, fishing, and the propagation of fish and aquatic life. Forest conservation helps retain the natural beauty of the community and protects dependent ecosystems. Trees cleanse water runoff and the air, provide shade to alleviate summer temperatures, and provide cover and food for a variety of wildlife. Since 1992, Montgomery County has required forest conservation under the Forest Conservation Law as part of the application process for land disturbance and development. The law is enabled by and modeled after the Maryland Forest Conservation Act of 1991. The Kemp Mill study area is completely built out, therefore, large areas of forested land exist only in Northwest Branch Stream Valley Park, Sligo Creek Stream Valley Park and Wheaton Regional Park (see Figure 6). The study area consists of approximately 650 acres of forest, of which 630 acres are in designated parkland. The parkland falls under the care of the M-NCPPC, Montgomery County Department of Park and Planning. The three forested park areas are made up of high-quality, maturing, mixed deciduous forests. Problems in maintaining these forests include alien invasive plants which displace native species, soil and canopy disturbances, a large deer population, and increasing recreational activities. In some cases, adjacent homeowners encroach on forested parkland with extensions of fencing and dumping of yard trim material, trash and debris. In 1991, the Park Commission of the M-NCPPC established a policy which prohibits mowing, planting, dumping or building structures on parkland without a permit. Additionally, the Maryland Wildlife and Heritage Division of the Maryland Department of Natural Resources identifies and inventories unique natural communities, valuable habitats, and rare, threatened and endangered species on a state wide basis. The Kemp Mill study area includes portions of Wheaton Regional Park and Northwest Branch Stream Valley Park which have been recognized by the Maryland Wildlife and Heritage Division as having significant forest habitat and plant species listed by the State as endangered, threatened or state watch-listed. General Wildlife Parkland provides habitat for birds, mammals, reptiles and amphibians. The portion of Wheaton Regional Park that lies within the Kemp Mill study area contains a sizable area of forest that supports several species of forest interior birds including scarlet tanager, ovenbird, Kentucky warbler, wood thrush, and veery. Areas bordering the Northwest Branch Stream Valley Park contain rich forest, floodplains, rock outcrops and wetland habitats that are important for amphibians and reptiles. Both areas support many common mammal species and some less common species, including mink. Deer Deer populations have increased in the Kemp Mill study area over the past decade, as they have in other parts of the County due to an abundance of good quality habitat and a lack of predators. The result has been an increase in deer-related auto collisions, complaints of damage to home landscapes and to natural vegetation in parks. These impacts are greatest on roads and in neighborhoods that border woods or other areas of natural vegetation. Deer-related auto accidents in the area have risen steadily over the past five years. A wildlife reflector system, designed to prevent animals from crossing roads at night when cars are present, was installed on Randolph Road in November of 1997, and data from this test site will be monitored over the next several years. Deer population surveys using helicopters were conducted in 1998 in Wheaton Regional Park and Northwest Branch Park and recorded populations of 60 and 120 deer per square mile, respectively. Most scientific studies recommend populations of less than 30 deer per square mile to ensure plant diversity and forest regeneration in addition to allowing other wildlife populations to thrive. A countywide deer management program was initiated in 1995 to better track deer impacts and implement efforts to reduce deer-human conflicts. The Washington metropolitan region, which includes all of Montgomery County, is currently classified as a "serious" non-attainment area under Federal air quality regulations with regard to ground-level ozone. Since 1990, the area has exceeded the one-hour ozone standard, on average, six days every summer. Federal air quality laws permit an average of only one exceedance per summer at a monitor location. Ground-level ozone (03) is an invisible gas formed when two pollutants — volatile organic compounds (VOC) and nitrogen oxides (NOx) — react in sunlight. The primary sources of these pollutants are utilities and other industries, motor vehicles, small gasoline powered engines, and small businesses that use solvents and cleaning solutions, paints, cleaners, and insecticides. After they are emitted, these pollutants can travel many miles before reacting to form ozone. On a typical summer day, over half of the pollutants that cause ozone in the Washington region comes from sources outside the region. Some sources are in other states, hundreds of miles away. Likewise, sources in the Washington area emit pollutants that travel many miles and eventually affect ozone concentrations in other regions and states. The Washington region has made considerable progress in reducing the emissions of VOC and NOx through previous actions of federal, state and local governments. The biggest impacts are due to the hightech motor vehicle inspection & maintenance programs, vapor recovery nozzles at service stations, reformulated gasoline, reformulated surface coatings, and new federal emission standards for both small and large engines. In addition to such actions, the Washington region's air quality plans set an upper limit on the overall tons of pollutants that motor vehicles can emit in the region. The region's Transportation Improvement Program and Constrained Long-Range Plan must conform to this limit. While the emissions of some air pollutants has decreased over the years, more progress will be necessary. In 1997, The U. S. Environmental Protection Agency (EPA) strengthened ozone and particulate matter standards in light of new scientific evidence that existing federal standards were insufficient to protect public health. As a result, the one-hour ozone standard has been replaced with a stricter eight-hour standard, and the particulate matter standard has been supplemented with twenty-four-hour and annual limits for very small particulate matter. These new standards pose additional challenges for reducing air pollution not only in the Washington region but other parts of the nation as well. To help meet those challenges, EPA has taken several important actions. First, it is requiring twenty-two states in the eastern third of the United States to substantially cut their emissions of NOx in order to reduce the amount of pollutants that drift from state to state. Each state can decide how emissions will be reduced, but most are expected to focus on utilities and big industrial plants that generate electricity by burning coal. Second, it has established a National Low-Emission Vehicle Program to further reduce the amount of pollutants emitted from the ever-increasing number of cars. Car manufacturers have voluntarily agreed to build cars with more stringent tailpipe emission standards, and each state will have the opportunity to adopt the new standards and implement the program. Third, to supplement the voluntary program, EPA is setting new emission reduction standards for diesel trucks, buses, and off-road heavy equipment and also requiring manufacturers to produce motor vehicles that are 77-95% cleaner than those on the road today. Fourth, the nation's refiners will be required to reduce sulfur levels in gasoline by 90%. These new actions will cause a significant reduction in emissions of VOC, NOx and particulate matter from these sources. Noise, most simply defined, is unwanted sound. The major source of noise in the Kemp Mill study area is roadway traffic. Roadway noise levels vary with traffic volume and speed, types of vehicles on the roadway and the type of roadway. There are few noise mitigation options where existing residential uses line the roadways. With property owners' cooperation, a fence or wall-type noise barrier could be constructed on private property along the contiguous roadway rights-of-way in situations where driveway access is not along the major road. However, acoustical treatment of an existing structure is often the most feasible option for affected homes and reduces interior noise levels by increasing the noise-reducing characteristics of the exterior facade, particularly windows and doors. Mitigation of noise impacts to and from redeveloping or newly developing properties is addressed during the development review process. Community sewer service is provided by the Washington Suburban Sanitary Commission (WSSC) to the entire study area (see Figure 7). Sewage flows to the Blue Plains regional wastewater treatment facility in the District of Columbia via Sligo Creek and the Northwest Branch trunk sewers. According to the WSSC, the trunk sewer along the length of the Northwest Branch, which borders the Kemp Mill study area, will be at or over capacity sometime between 2010 to 2020. The Sligo Creek trunk sewer has recently been upgraded and should not require relief in the foreseeable future. When new or upgraded relief sewers are needed, WSSC prepares a facility plan. Community water is also managed and supplied by WSSC for the entire Kemp Mill study area. Water is drawn from the Potomac and Patuxent rivers, treated and distributed throughout Montgomery County. Water supply will be able to meet the demand for the Kemp Mill study area for the foreseeable future. Lifestyles and daily activities of individuals greatly influence pollutant levels. Practice such as overuse of garden fertilizers, pesticides, and improper disposal of household chemicals introduce nutrients and toxic substances into stormwater management facilities. A number of programs are in place to increase awareness of environmentally friendly" practices, and public involvement activities are undertaken by both public agencies and private groups. Currently, Montgomery County has a wetlands and watershed educational program called the Stream Striders. This program educates individuals regarding the importance of maintaining the integrity of the wetlands and stream buffers. Stream Striders are trained in the areas of basic stream ecology, the local watersheds of the County and their relevance to the Chesapeake Bay. These individuals are then able to educate people in their own community. Save-Our-Streams (SOS), a state-wide volunteer organization, educates citizen volunteers and community organizations to clean, monitor, and protect Maryland's waterways. SOS addresses the root causes of stream pollution by educating and supporting people to perform common-sense projects to solve them. Other non-profit, environmental membership organizations such as the Audubon Naturalist Society, which sponsors a volunteer stream monitoring program, provide ongoing conservation and educational programs.
Countywide Stream Protection Strategy Management Categories The CSPS developed five categories that are based on existing stream quality, imperviousness and land use. Following is a brief discussion of each management category. 1. Watershed Preservation Areas
2. Watershed Protection Areas
3. Watershed Restoration Areas
4. Urban Watershed Management Areas
5. Agricultural Watershed Management Areas
Countywide Stream Protection Strategy
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