EA Project No.: 63343.01 Version: FINAL Page 6-1 EA Engineering, Science, and Technology, Inc., PBC February 2019

6. WATER QUALITY

There has been pressure to decrease nitrogen, phosphorus, and sediment concentrations entering the (U.S. EPA 2010). In 2010, EPA established a TMDL for nitrogen, phosphorus, and sediment for the Chesapeake Bay. These contaminants have been linked to declines in fish populations and SAV. The Northern Chesapeake Bay and associated watersheds have been identified as one of the contributing sources of nitrogen, phosphorus, and sediments to the Chesapeake Bay through runoff from urban and agricultural areas (U.S. EPA 2010). Because coastal resiliency measures would result in alterations to the shoreline along the Chesapeake Bay, the , and tributaries, this may serve as an opportunity to decrease nutrient and sediment loading at sites where they ultimately enter the bay.

Erosion Control Options

Breakwaters, groins, and revetments are engineered structures designed to control and prevent erosion. Strategically placing these structures in areas that are eroding would help to decrease the mass of sediment entering the Chesapeake Bay.

Wetlands can also be designed to limit erosion as the root systems of plants serve to stabilize sediments. Water movement is slowed as it passes through a wetland, which can result in further sedimentation because of Stokes’ Law. An additional benefit of wetlands is that they can be designed to decrease concentrations of contaminants in water (Kadlec and Wallace 2008; Rodgers and Castle 2008).

Constructed Wetland Treatment Systems (CWTS) for Phosphorus and Nitrogen Removal

Constructed wetland treatment systems (CWTS) have some similarities with natural wetlands and also differ in a number of ways. CWTS are similar in that they use natural processes that can be found in natural wetlands. Another similarity is that CWTS contain hydrosoil, overlying water, and vegetation, all components of natural wetlands as well. CWTS are fundamentally different from natural wetlands in that they are engineered to promote conditions that drive natural or biogeochemical processes. Throughout the active life of a CWTS, conditions will need to be monitored and specific corrective actions will need to be initiated if wetland conditions deviate from those needed for contaminant removal. This process can be relatively uncomplicated, such as monitoring if sediments are reducing or aerobic with a probe. This will allow for wetland conditions to remain relatively stable and will allow for the removal of nitrogen and phosphorus from overlying waters. Wetlands designed for the removal of phosphorus and nitrogen have been successfully designed to achieve efficient and effective nutrient removal (Huett et al. 2005; Beebe et al. 2013, 2015). In addition to nutrients, CWTS have been designed for the removal of metals, pesticides, and complex mixtures (e.g., runoff, process waters).

There are many processes that can alter the form of phosphorus in overlying water so that it can be transferred to the sediment phase. Under aerobic conditions, phosphate, a bioavailable form of phosphorus, is transferred to the sediment phase (Wetzel 2001). To promote aerobic

Planning for Coastal Resiliency in the Northern Chesapeake Bay EA Project No.: 63343.01 Version: FINAL Page 6-2 EA Engineering, Science, and Technology, Inc., PBC February 2019

conditions in wetlands the components of the wetland can be altered (e.g., hydrosoil, vegetation, and overlying water). For example, hydrosoils can be selected with low organic carbon concentration so as not to promote microbial degradation of organic carbon resulting in anaerobic conditions. Additional processes that can be used to transfer phosphorus from the water to sediments include adsorption and precipitation (Vymazal 2007). Amendments of the hydrosoil with zeolite can promote adsorption and improve the removal of phosphate from water (Sakadevan and Bavor 1998).

Nitrogen in the form of ammonia can be removed from contaminated waters by microbial transformation to nitrogen gas. This process requires aerobic conditions for the nitrification of ammonia to nitrate then nitrate and reducing conditions for the ultimate denitrification to nitrogen gas. Conditions can be altered to promote aerobic conditions as previously mentioned for phosphate. Alternatively, wetland conditions can be altered to promote anaerobic conditions. An example would include amending sediments with a degradable carbon source (e.g., cattail detritus during senescence).

Specific design elements would need to be considered to engineer CWTS for nutrient removal along the shoreline. Some preliminary sampling could be conducted to identify areas with relatively elevated concentrations of nutrients contributing to Chesapeake Bay nutrient contamination. An additional consideration may be constructing passive wetlands between the CWTS and the Chesapeake Bay. Passive wetlands are not specifically designed for contaminant removal. The passive wetlands could act as a protective barrier for the CWTS. Storm surge from major storm events may pose risks to the biogeochemical processes of the CWTS.

Water Quality Monitoring Stations

USGS water quality monitoring stations within the Chesapeake Bay adjacent to shorelines and in tributaries in Harford, Cecil, and Kent County, are identified in Figures 6-1 through 6-3, respectively. Water quality monitoring for nutrient and sediment concentrations prior to, during, and post-construction of coastal resiliency measures and nutrient reduction strategies (e.g., CWTs) can provide a measurement of their performance for Chesapeake Bay.

Planning for Coastal Resiliency in the Northern Chesapeake Bay VICINITY MAP

Conowingo Dam Susq R Little Elk Creek

PA

Broad Creek Map Extent Conowingo Dam Susq R NJ

WV

MD Cecil County DC Station 1579550 DE SUSQUEHANNA RIVER NEAR DARLINGTON, MD VA (! Northeast River Furnace Bay

Susquehanna River Legend L Susquehanna River County Boundary 8 Digit Watershed Boundary Harford County 8 Digit Watershed Boundary with TMDLs Station XKH2949 Atkisson Reservoir Havre de Grace(SUS) (! USGS Monitoring Station (! Eyes on the Bay ! Swan Creek ( Continuous Monitoring Station

Bynum Run Little Gunpowder Falls

Station 1581752 PLUMTREE RUN NEAR BEL AIR, MD (! Chesapeake Bay

Station XJG7461 Station XJG7035 Church Point(BCP) Otter Point Creek(OPC) (! Lower (! Aberdeen Proving Ground Lower Map Date: 1/30/2019 Lower Gunpowder Falls Source: ESRI 2017, USGS 2017 Aberdeen Proving Ground Projection: WGS 1984 UTM Zone 18N Meter

Station 1585075 FOSTER BRANCH NEAR JOPPATOWNE, MD Station XJG4337 Upper Chesapeake Bay (! Lauderick Creek(LAU) (! (! Station XJF4289 Station XJG2718 Mariners Point Park(MPP) APG at Edgewood(GUN) $ (! 0 2 4 Bush River Miles Gunpowder River

Back River Aberdeen Proving Ground

Middle River - Browns Stillpond-Fairlee Kent County FIGURE 6-1 Middle Watersheds and Monitoring Stations Harbor Middle Chesapeake Bay Harford County Upper Chester River Planning for Coastal Resiliency in the L N Br \\lovetongis\gisdata\StateandLocal\Northeast\Maryland\6334301_SusquehannaRiver_Study\MXD\HarfordCounty\Figure6-1 Harford Co Watershedsand Monitoring Stations.mxd mdhruv Northern Chesapeake Bay VICINITY MAP

Christina River

PA

Broad Creek Conowingo Dam Susq R Octoraro Creek Map Extent NJ

Big Elk Creek WV Little Elk Creek MD

Cecil County DC DE VA Station 1579550 SUSQUEHANNA RIVER NEAR DARLINGTON, MD Northeast River (!

Furnace Bay Legend Aberdeen Proving Ground Deer Creek Susquehanna River County Boundary

Station XKI5022 8 Digit Watershed Boundary L Susquehanna River Charlestown(NOR) ! (! ( USGS Monitoring Station Maryland Eyes on the Bay Upper Elk River Station XKI3890 (! Continuous Monitoring Station Locust Point Marina(LOC) (! Station XKH2870 Stump Point(STU) (! Harford County (! Northeast River Station XKI2087 Swan Creek Station XKH2797 Carpenters Point(CAR) Back Creek(CND) (! Back Creek Bynum Run

Chesapeake Bay Lower Elk River Station XKI0256 Atkisson Reservoir Upper Chesapeake Bay Hollywood Beach(HOL) (!

Map Date: 1/30/2019 Source: ESRI 2017, USGS 2017 Projection: WGS 1984 UTM Zone 18N Meter Elk River Bohemia River Station XJI8369 Long Point(BOH) (!

Lower Winters Run Bush River Aberdeen Proving Ground Bohemia River Aberdeen Proving Ground $ Little Gunpowder Falls 0 2 4

Miles

Bird River Gunpowder River Station XJI2396 Sassafras River Sassafras River Budds Landing(BUD) Bird River Station XJI1871 (! Georgetown Yacht Basin(GYB) FIGURE 6-2 (! Watersheds and Monitoring Stations Stillpond-Fairlee Kent County Cecil County Planning for Coastal Resiliency in the

\\lovetongis\gisdata\StateandLocal\Northeast\Maryland\6334301_SusquehannaRiver_Study\MXD\CecilCounty\Figure 6-2 Cecil CoWatersheds and MonitoringStations.mxd mdhruv Aberdeen Proving Ground Upper Chester River Northern Chesapeake Bay VICINITY MAP Bird River Station XJH2362 Sassafras River Cecil County Station XJI2396 Betterton Beach(BET) Budds Landing(BUD) Bush River (! (! PA Station XJH1222 (! Camp Tockwogh(CTW) Station XJI1871 (! Sassafras River Aberdeen Proving Ground Georgetown Yacht Basin(GYB) Gunpowder River NJ Upper Chesapeake Bay Map Extent WV Aberdeen Proving Ground

MD

DC DE VA Kent County

Stillpond-Fairlee Legend Aberdeen Proving Ground Station 1493112 County Boundary Chesapeake Bay CHESTERVILLE BRANCH NEAR CRUMPTON, MD (! 8 Digit Watershed Boundary Middle Chester River Station CHE0348 (! USGS Monitoring Station Deep Landing(DEE) (! Maryland Eyes on the Bay (! Continuous Monitoring Station Upper Chester River Station XIG2853 Tolchester(TOL) (!

Middle Chesapeake Bay

Station XIH0077 Langford Creek Rolphs Wharf(ROL) (!

Station XHG8442 Map Date: 1/30/2019 Gratitude Marina(THX) Source: ESRI 2017 (! Projection: WGS 1984 UTM Zone 18N Meter Southeast Creek $ 0 2 4

Lower Chester River Miles

Tuckahoe Creek Chester River Upper Choptank

Corsica River

FIGURE 6-3 Lower Chesapeake Bay Watersheds and Monitoring Stations Kent Island Bay Kent County Planning for Coastal Resiliency in the \\lovetongis\gisdata\StateandLocal\Northeast\Maryland\6334301_SusquehannaRiver_Study\MXD\KentCounty\Figure 6-3 Kent CoWatersheds and Monitoring Stations.mxd mdhruv Northern Chesapeake Bay