Sediment
Predicted Area of Bay Dead Zone Released
Each year, the University of Maryland Center for Environmental Science, the University of Michigan, and the National Ocean and Atmospheric Association collaborates on models predicting the size of the dead zone that will be found in the main stem of Bay over the summer months. Using USGS data on nutrient and sediment loads entering the Bay from the first half of this year, the models can pretty accurately predict how big this dead zone will be. This year’s prediction: the dead zone will be “slightly smaller-than-average.”
Please see the Chesapeake Bay Program for more information.
The Potomac Conservancy Releases Report Card for River’s Health
The Potomac Conservancy has released their biennial report on the Potomac River, the second largest river draining into the Chesapeake Bay. The health of the Potomac River, due to its large area and population size within watershed boundaries, is very important to the health of the Bay. The Potomac Conservancy has issued the River a grade of B- in terms of overall health. Rising from a D to a C to a B- over the past ten years, the state of the Potomac River is improving. However, a number of different areas need to be addressed to continue to improve water quality in the Potomac and the Chesapeake.
Figures 1, 2, and 3 show changes to nitrogen, phosphorus and sediment loads in the Potomac from 1985 to 2014. Over this time period, there have been load reductions from these three major sources of pollution.
The improvements in overall health of the Potomac River are due in large part to reduced sediment and nutrient loads from agricultural activity and wastewater treatment plants.
Wastewater treatment facilities have undergone a number of upgrades to ensure that water discharged from facilities contains smaller concentrations of nitrogen and phosphorus. With higher standards now required by the EPA, upgrades to many wastewater treatment facilities in the watershed have contributed to cleaner waters in the Potomac River. (Between 2011 and 2015, there was a 13% increase in facilities adhering to stricter EPA standards).
Agriculture in the Potomac River watershed has likely contributed fewer nutrient loads because agricultural activity within the region is declining, as land is converted to accommodate urban sprawl. The Potomac River, which flows from Fairfax Stone, West Virginia to Point Lookout, Maryland, covers a large urban and suburban area. So, while agricultural runoff is decreasing, nitrogen and phosphorus loads in stormwater runoff from developed areas is still a major concern.
Within this report, the Potomac Conservancy grades a number of sub-indicators of river health, such as fish population, underwater grass abundance, and recreational use. These ratings are then examined together to determine overall health. While overall health of the river is improving, there are some areas that are actually doing worse, or showing no marked improvement from previous years. This is the case for water clarity and underwater grass abundance, which received a grade of C-. These two factors are important indicators of health in the Chesapeake Bay (underwater grasses provide food and habitat for marine species, and filter sediments and nutrients in the water, which can improve water clarity). Going forward, I would definitely like to see higher rates of recovery for these two indicators.
There is mixed news for the river’s fish populations. Certain species, such as shad, white perch, and smallmouth bass are experiencing population growth. The Bay’s rockfish population, however, has declined slightly over the past ten years. Many fish species are at continued risk of predation from invasive species such as the blue catfish and snakehead.
In terms of tidal water quality, certain conditions are improving, although numbers for dissolved oxygen, clarity, and chlorophyll A (a measure of algae), vary year to year. Chlorophyll A levels have declined over the last fourteen years. See Figure 4 below.
[We have been taking water samples from both the Potomac River (out of Great Falls), and Antipoison Creek, (which is just off of the Chesapeake Bay, close to where the Rappahannock River meets the Bay), and interestingly, found higher chlorophyll levels in Antipoison Creek. I’ll post more on our results later.]
There was good news for recreational land use, which has gone up since the last report. Recreational use of waterways can be an indicator of improved water quality.
Protected land area has increased, from 1.8 million acres in 2011 to 1.9 million acres in 2013. This area equates to 26.6 percent of land in the Potomac River watershed.
Concerns going forward include rates of deforestation and development in unsuitable areas, and runoff from suburban and urban regions. Agricultural areas, while declining, could still do with the enforcement of Best Management Practices (BMPs). The amount of forested buffers (streamside vegetation which reduces agricultural runoff into tributaries), received a grade of C-.
It’s important to keep in mind that the results in this report do not come from the most current data. The Potomac Conservancy gathers its information from a number of institutions, such as the EPA and the USGS. There is a couple years lag time on data for many of these sub-indicators of overall health.
Information and graph source: State of the Nation’s River 2016, Potomac River Conservancy, http://potomacreportcard.org.
USDA Awards Four Bay States $1 Million Each for Cleanup Efforts
Virginia, West Virginia, New York and Delaware are set to receive $1 million each from the U.S. Department of Agriculture (USDA) as part of a federal effort to improve water quality in the Chesapeake Bay. Money will go toward farmers in the Bay watershed with stream access on their properties. Specifically, the money supports planting of vegetated streamside buffers on agricultural lands.
These vegetated streamside buffers, or riparian buffer zones, act as physical barriers to livestock, which might otherwise have direct access to pollute streams. Riparian buffer zones also reduce sediment and nutrient loads, running off from farmland, and entering the watershed.
The USDA is able to offer federal funds to Bay states under their Conservation Reserve Enhancement Program (CREP). According to the USDA, CREP and USDA funds (about $500 million in total), supplied to Bay states since 1996, have resulted in the planting of 7000 miles of riparian buffer zones, and “have prevented an estimated eight million tons of sediment, 16 million pounds of nitrogen, and four million pounds of phosphorus from entering the waters of the watershed.” (See http://www.usda.gov/wps/portal/usda/usdahome?contentid=2015/10/0271.xml&contentidonly=true).
The USDA CREP program is voluntary. Funds are being offered to agricultural landowners who agree to participate in planting riparian buffer zones, and require financial support.
The $4 million going to Virginia, West Virginia, New York and Delaware is a first round of funding. A second round from the USDA will likely target Maryland and Pennsylvania- states with significant amounts of agricultural runoff to the Chesapeake Bay.
Chesapeake Bay Foundation Will Not Appeal VA Court Decision
Last month I posted about the Richmond Circuit Court ruling against the Chesapeake Bay Foundation (CBF) in the case of CBF vs. Virginia, (see here). In this case, CBF argued that the Virginia Department of Environmental Quality and the State Water Control Board should have included livestock exclusion from streams in a permit that both agencies passed late last year on land application of animal waste.
The Richmond Circuit Court, after reviewing the Virginia Pollution Abatement Permit in question, decided that given the lack of clarity in the permit’s wording, Virginia’s Department of Environmental Quality and the State Water Control Board were able to make their own call on the issue of livestock exclusion from streams. With this ruling, CBF’s case was rejected. As of last week, CBF has decided not to appeal this decision.
Chesapeake Bay Foundation Files Suit Against Virginia
Kudos to the Chesapeake Bay Foundation (CBF) for moving ahead on a major water quality issue in Virginia. This week CBF filed suit against Virginia’s Department of Environment Quality (DEQ) and the State Water Control Board over failure to enforce state regulations for livestock farmers.
One of the management practices Virginia has said it will implement to reduce water pollution in the Chesapeake Bay watershed is making sure all farmers keep their livestock out of streams and rivers through the use of fences and stream buffers. CBF has found that many Virginia livestock farmers are not implementing these management practices. This is thanks to the Virginia Pollution Abatement Permit, approved last year by the DEQ and the Water Control Board for a ten-year period. This permit does not require the state’s largest livestock farms (cattle, pig, poultry) to fence and buffer streams to which the livestock have access.
CBF’s challenge to the DEQ and the State Water Control Board, should it be upheld in court, will improve a flawed permitting process, ensure that Virginia does its part to reduce water pollution, and ultimately improve the health of the Chesapeake Bay.
Fencing off streams and rivers from livestock reduces water quality issues in the tributaries and mainstem of the Chesapeake Bay. When livestock have wading access to bodies of water, they are able to pollute streams and rivers with their waste, adding to the nitrogen and phosphorus runoff that enters the Bay. Livestock also erode stream banks, depositing sediment directly into the water, which makes its way downstream and eventually reaches the Bay.
By allowing farms to give their livestock access to streams and rivers, the DEQ and State Water Control Board are not enforcing the State Water Control Law, which calls for a reduction and prevention of water pollution. Furthermore, by not enforcing regulations that curb nitrogen, phosphorous and sediment runoff from agriculture, Virginia is violating its agreement with the EPA (in the Clean Water Blueprint) to reduce nutrient and sediment pollution entering the Bay from state waters.
The Richmond Circuit Court will hear arguments for this case this Thursday, July 2. Updates to come.
The original press release from CBF can be found here.
A Review of the EPA’s Assessment of Virginia’s Bay Cleanup Progress
By Neil Saunders
According to the EPA’s recent interim assessment of pollution in the Chesapeake Bay, Virginia is on track to meet its TMDL targets for both nitrogen and phosphorus, but is off track to meet its targets for sediment. Three out of four sectors- agriculture; wastewater treatment plants and onsite systems; and offsets and trading- are under the lower “ongoing oversight” designation, with the remaining sector- urban/suburban storm water- under the intermediate “enhanced oversight.” According to the EPA’s “Next Steps,” urban/suburban storm water may be upgraded to “ongoing oversight” in 2016 provided Virginia completes certain MS4 (define) permitting requirements.
What do these results mean going forward? At this stage in the overall TMDL process, it is an encouraging sign that Virginia, which contributes significant nutrient levels to the Bay, is on track to meets its 2017 targets for nitrogen and phosphorus. It is also encouraging that Virginia appears close to receiving an upgrade in oversight level for the urban/storm water sector, which would place all of the state’s programs under the lower “ongoing oversight” level. Until all practices are in place (which isn’t expected until 2025), this is generally what we hope to see in all of the Bay States’ interim assessments.
Despite the largely positive results, however, there are still areas where Virginia can improve. Sediment levels remain an issue for the state, and will require additional measures to achieve the necessary reductions targets by 2017. This will likely prove challenging, given the fact that the EPA’s current projections of sediment levels over the past decade are higher than were initially anticipated, meaning more sediment has been entering the Bay than previously thought. Another concern is that, although the EPA’s model projections place the state’s agriculture practices on track to meet the 2017 targets within that sector, the fact that Virginia maintains a voluntary approach to nutrient management makes it difficult to accurately measure. The EPA expects that Virginia will work with the Chesapeake Bay Program Office to “project the necessary pace of voluntary agriculture program implementation to stay on track with nutrient and sediment reduction goals and set milestones accordingly.”
The interim “results” are based largely on models that project future nutrient and sediment levels, and incorporate many activities, or practices, that have not yet been implemented. Unless the states actually follow through on their commitments, many of the positive projections will be unrealized. Therefore, it is crucial that the states continue to take any and all additional measures that are necessary to restore the Chesapeake Bay. There is still a long way to go and a lot more that needs to be done.
The interim assessments were released to for the six Bay States’ 2014-2015 milestones. These assessments, which form part of the EPA’s overall accountability framework under the 2010 Chesapeake Bay Total Maximum Daily Load (TMDL) for the entire Chesapeake Bay watershed, play an integral role in evaluating the progress of the Bay States towards meeting their respective pollution reduction targets, and are used to identify areas of concern that require additional measures to meet those targets.
The EPA and Bay States are currently in Phase II of a three-phase, fifteen year process of the TMDL, which means that they are continuing to work towards implementing practices by 2017 that will meet sixty percent of the total pollution reductions needed to clean the waters of the Chesapeake Bay. The third and final phase is to be completed by 2025, and requires 100 percent of the pollution reductions measures to be in place.
A Review of the EPA’s Assessment of Maryland’s Bay Cleanup Progress
By Neil Saunders
According to the EPA’s recent interim assessment of pollution in the Chesapeake Bay, Maryland is presently on track to meet the 2017 TMDL reduction targets for two out of the three major pollutants in the Bay: phosphorus and sediment. Maryland is not on track to meet the target reductions for the third major pollutant, nitrogen. New information obtained by the EPA shows that Maryland is actually contributing more nitrogen to the Bay than previously thought. Therefore Maryland must plan to implement even more effective practices to ensure that it will meet its 2017 targets for nitrogen.
So what do these results mean for the Chesapeake Bay going forward? For one, Maryland is the only state currently under the lower “ongoing oversight” for each sector category that the EPA assesses: agriculture; urban/suburban stormwater; wastewater treatment plants and onsite testing; and offsets and trading. While this is far from encouraging overall, it does demonstrate that Maryland, the state most synonymous with the Chesapeake Bay, it making positive strides towards meeting its reduction targets. The EPA expects Maryland to implement additional measures to reduce nitrogen pollution.
Also, much of the progress made in Maryland, including the recently proposed phosphorus management regulations, still must be implemented to achieve the projected pollution reductions. At this stage in the TMDL process, many of the projections are based on practices that have yet to be implemented. It is critical, that Maryland continue efforts to put practices into place. Sometimes, this is easier said than done. Similar regulations to the Phosphorus Management Tool regulations have been pulled and/or delayed in the past (the environmental community has advocated for stricter phosphorus management for over a decade now), so it is crucial for Maryland and the Department of Agriculture to follow through with implementation.
The interim assessments were released for the six Bay States’ 2014-2015 milestones. These assessments, which form part of the EPA’s overall accountability framework under the 2010 Chesapeake Bay Total Maximum Daily Load (TMDL) for the entire Chesapeake Bay watershed, play an integral role in evaluating the progress of the Bay States towards meeting their respective pollution reduction targets, and are used to identify areas of concern that require additional measures to meet those targets.
The EPA and Bay States are currently in Phase II of a three-phase, fifteen year process of the TMDL, which means that they are continuing to work towards implementing practices by 2017 that will meet sixty percent of the total pollution reductions needed to clean the waters of the Chesapeake Bay. The third and final phase is to be completed by 2025, and requires 100 percent of the pollution reductions measures to be in place.
Sediment Buildup Behind the Conowingo Dam
On Monday, an article appeared in The Washington Post on the Conowingo Dam in Maryland, and Governor Larry Hogan’s efforts to have the sediment behind the dam dredged. While sediment buildup behind the Dam poses an environmental threat to the Chesapeake Bay, and I think the Dam should be dredged, I don’t think this is the biggest threat to the health of the Bay. I would also like to see Hogan focus on reducing nutrient loads to the Chesapeake, from agricultural and urban/suburban runoff in Maryland. That being said, it’s good to see the current Governor tackling water quality issues for the Chesapeake Bay, and committed to reducing sediment loads to the Bay from the Conowingo Dam.
Located at the Southern end of the Susquehanna River, the Conowingo Dam was constructed in 1929. Since that time, (1929-2012), about 470 million tons of sediment have been transported from the Susquehanna into the Conowingo Reservoir, where 280 million tons of sediment have been trapped by the dam, and 190 million tons have gone on to reach the Chesapeake Bay (USGS, 2014).
Some reports differ on whether the Conowingo Dam has reached storage capacity for sediment. The USGS says yes; a 2010 EPA study said the Dam had not yet reached full capacity, and likely would not for another 15-20 years. However, the EPA stated in this same 2010 report, that, “once the Conowingo Reservoir reaches the sediment trapping capacity, the sediment and nutrient loads delivered to the Chesapeake Bay via the Susquehanna River will equal the load delivered into the reservoir system. Once storage capacity is reached, the nitrogen load will increase by 2%; the phosphorus load will increase by 40%; and the suspended sediment load will increase by at least 150%” (EPA, 2010, T-3).
The Conowingo Reservoir holds nutrients and sediment from the Susquehanna River, a tributary of the Chesapeake Bay known for its high loads of nitrogen, phosphorus, and sediment. The Susquehanna carries runoff to the Bay from agricultural fields, and urban and suburban regions in the upper half of the Chesapeake Bay watershed, from parts of New York, Pennsylvania, and Maryland. This river delivers half of the Bay’s freshwater, and contributes 40% of the nitrogen, 20% of phosphorus, and a significant amount of sediment to the Chesapeake (CBF, 2006). Should the Conowingo Reservoir reach full capacity, even more nitrogen, phosphorus and sediment will reach the mainstem of the Chesapeake Bay from the Susquehanna.
The most significant concern in regards to the Conowingo Dam, is the buildup of sediment. Major storm events cause sediment backed up behind the Dam to overflow directly into the Chesapeake Bay. When the Conowingo Reservoir is at full capacity, this risk of overflow increases. Sediment is an issue for the Bay, when excess loads delivered to the Bay block out sunlight for underwater grasses, which they need to survive. Sediment can also cover oyster beds, suffocating mature and juvenile oysters. Sedimentation can lead to poor water quality, impacting other fish and shellfish species in the estuary.
To reduce the risk of sediment and nutrient overflow from the Conowingo Dam, Governor Hogan is calling for dredging of sediment behind the dam, and wants the dam’s operating company, Exelon Corp., to pay for this estimated $250 million project. Exelon is fighting back, citing studies from the Maryland Department of the Environment and the Army Corps of Engineers that state nutrients are far more harmful to the Bay than sediment. Exelon is also arguing that the sediment from the Dam is only harmful to small sections of the Bay, and contributes a very small percentage of sediment to the estuary, (the Post article says less than 5%).
I agree that nutrients from agricultural practices, and urban and suburban runoff pose a larger threat to the Bay as a whole, and Hogan should focus more energy on reducing nutrient loads from these sectors. However, if the Conowingo Reservoir is indeed at full capacity, the Bay, even a small portion of it, cannot risk a 150% increase of sediment load, which is likely to happen with a large storm event. (For example sediment scour, or removal of sediment from behind the Dam, reached millions of tons for major storm events in the past. Tropical Storm Agnes in 1972 resulted in 13.5 million tons of sediment scour. A more recent major storm event, Tropical Storm Lee in 2011, resulted in 3.5 million tons of sediment scour). An increase in sediment load this large is sure to cause water quality issues in the upper reaches of the Bay, and harm fish and shellfish species in this region.
Calls for Operators on Conowingo Dam to Reduce Pollution, Improve Fish Migration Routes
This week I’ve been working on a paper on dam construction and deconstruction in the United States for a class on Environmental Conservation and the American Landscape. I thought it was pretty interesting to come across an article, published May 5, on the Conowingo Dam in the Chesapeake Bay watershed. The Chesapeake Bay Foundation has recently called on the company that oversees this hydroelectric dam in Maryland to address environmental concerns. Environmental issues associated with this and many dams in the country include a reduction in river levels, a prevention in flow of nutrients and plants, flooding, and an inability of migrating fish to travel up and down a river as needed. Of particular concern in the Chesapeake region is the buildup of sediment behind dams, which can runoff downstream in large storms. The excess sediment can result in sediment pollution, and disrupt cleanup goals in the lower reaches of the Chesapeake Bay. CBF Testimony Calls on Exelon to Help Mitigate Pollution and Improve Fish Passages
Chesapeake Bay environment and water quality blog 