The proposed construction of the Mattawoman Power Plant (Mattawoman Energy Center) will have a major adverse impact on the Brandywine area due to increased traffic and site activities over a several-year construction period. The map in Figure 1 shows the relationship between the power plant, Brandywine Road and other major transportation arteries in the area.
Traffic Congestion: Even now, Brandywine Road is a heavily trafficked commuting and truck route. Traffic is especially congested during the rush hours on Brandywine Road both east and west of the oft-jammed area where Route 5, U.S. 301 and Brandywine road come together (shown as area within yellow dashed line in Figure 1).
Figure 1: Brandywine Road area near the intersection of U.S. 301 and Rte 5.
According to the Maryland Power Plant Research Project (PSC, MDE), Environmental Report, the plant’s construction would require a workforce of 275 employees on average over an approximately three-year period. In the peak construction period, up to 645 construction workers and other personnel would commute to and from the site. In addition, the construction will entail frequent deliveries of equipment and supplies. Construction will require large numbers of diesel trucks, including some heavy-duty trucks.
The PPRP’s Environmental Report acknowledges the problem, “During the peak construction period, however, the intersections of MD 381 with Missouri Avenue and with the site access driveway would also operate at an unacceptable LOS during the evening peak hour, in addition to operational issues at the two signalized intersections. ”
This conclusion is especially significant given the congestion that already takes place at the intersection of Brandywine Road and Missouri Avenue as well as the facilities located there, including: the Brandywine Elementary School, a housing facility for seniors and commercial facilities. (See Figure 2). What impact will higher traffic levels have on cars and buses bringing students and staff to the school? How will access and parking at Chapel of the Incarnation and Community Support Systems (housed in the Chapel building) be affected by construction traffic? As Figure 1 shows there is a major health facility (MedStar) on Brandywine Road between U.S. 301 and Missouri Avenue; impact of congestion?
Figure 2: The crossroads. See text for information.
Pipelines along Brandywine Road: The Mattawoman Plant will also require construction of (a) gas pipeline (b) cooling water pipeline and (c) large transmission line towers right along Brandywine Road between the plant site and Rt. 301 (see Figure 2). The state’s environmental report acknowledges that pipeline construction will further worse congestion along Brandywine Road. Consider the following excerpt from the PPRP Environmental Report.
Construction of the pipelines would involve trenching to the maximum extent possible and directional drilling under major roads, rail lines or sensitive resources traversed by the facility. Trenching within the ROW of roadways could affect traffic flows where construction is staged, although construction is expected to be sequenced. …. In addition, access to private driveways and businesses along the reclaimed water pipeline route could be temporarily disrupted by excavation activities. 
The CSX railroad crosses Brandywine Road close to the Mattawoman Site; to the extent that the railroad is used to deliver equipment and material to the site, additional backups and increased emissions (including diesel emissions from train engines) can be expected.
Air Pollution and health impacts: Prince George’s County is part of the DC-VA-MD ozone non-attainment region, with National Ambient Air Quality Standard exceedances reported at the nearest monitoring site (Upper Marlboro). And numerous exceedances of the 8-hour ozone ambient air standard have occurred over the past five years. This means that the ambient air in the area is unhealthful, especially for sensitive individuals including children, the elderly, and those with chronic respiratory disease such as asthma.
Construction of the Mattawoman power plant will further deteriorate air quality in the Brandywine area causing a probable increase in adverse health impacts. Motor vehicle emissions include: Emissions of concern include: fine particulate matter (PM2.5), diesel exhaust (ultrafine particulates, carbon particulates, etc.), carbon monoxide (CO), hydrocarbons (HC) and oxides of nitrogen (NOx). HC and NOx react in the air when exposed to sunlight to form ozone and NO2. The World Health Organization (WHO) has designated diesel exhaust as a human carcinogen.
The increases in traffic volume will increase motor vehicle emissions and air pollution levels for two reasons: (a) higher vehicle density causes higher total emissions (b) slower speeds, backups and idling all which increase motor vehicle related impacts—including the highly toxic emissions associated with diesel trucks. This relationship is shown in Figure 3 excerpted from a Federal Highway Administration study.
How will increased concentrations and repeated exposures to air pollutants affect the most vulnerable people, children—i.e. students at the Brandywine Elementary school, the elderly (those at the CSS senior home , those with chronic respiratory and cardiovascular disease? Neither Mattawoman Energy, LLC, the PSC, the PPRP, nor the Maryland Department of Environment (MDE) have done the analysis on traffic emissions required to demonstrate that construction of the power plant can proceed without serious adverse impacts on the health of residents and workers in the Brandywine area.
These problems are heightened by the fact that three power plants are already operating or under construction within an 8-mile radius of Brandywine. Mattawoman Energy would be the fourth. The Keys Energy Center (N. Keys Road), under construction, is less than a mile from the Mattawoman site.