5

Strategies for Meeting the Goals

The Chesapeake Bay estuary is one of the nation’s unique and valuable environmental resources. Preservation of this important ecosystem and proper evaluation and maintenance of its water quality are high priorities for the federal government, the Bay jurisdictions, and their citizens. As discussed in Chapter 1, the Chesapeake Bay Program (CBP) has established water quality goals for the Bay to address the adverse effects caused by nitrogen, phosphorus, and sediment loading from human activities and land development in the watershed. The primary sources of these pollutants include animal and crop agriculture, urban and suburban runoff, wastewater discharge via wastewater treatment plants and septic systems, and air pollution (see Chapter 1).

Bay jurisdictions have developed broad watershed implementation plans (WIPs) to implement practices by 2025 that will ultimately reduce nutrient and sediment loads by the amount necessary to attain the Bay water quality criteria. Reaching these goals will not be easy, however, and will require substantial commitment and, likely, some level of sacrifice from all who live and work in the Bay watershed. Jurisdictions will not only have to make significant reductions in current loads, but they will need to make additional cuts to address future growth and development over the next 15 years. Implementation strategies for the near-term have been developed for the first of the two-year year milestone periods, and detailed strategies through 2017 are in development through the Phase II WIP process. To reach the long-term load reduction goals, Bay jurisdictions and the federal government will need to consider a wide range of strategies, including some that are receiving little, if any, consideration today. Additionally, Bay part-



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 125
5 Strategies for Meeting the Goals T he Chesapeake Bay estuary is one of the nation’s unique and valuable environmental resources. Preservation of this important ecosystem and proper evaluation and maintenance of its water quality are high priorities for the federal government, the Bay jurisdictions, and their citi- zens. As discussed in Chapter 1, the Chesapeake Bay Program (CBP) has established water quality goals for the Bay to address the adverse effects caused by nitrogen, phosphorus, and sediment loading from human activi- ties and land development in the watershed. The primary sources of these pollutants include animal and crop agriculture, urban and suburban runoff, wastewater discharge via wastewater treatment plants and septic systems, and air pollution (see Chapter 1). Bay jurisdictions have developed broad watershed implementation plans (WIPs) to implement practices by 2025 that will ultimately reduce nutrient and sediment loads by the amount necessary to attain the Bay water quality criteria. Reaching these goals will not be easy, however, and will require substantial commitment and, likely, some level of sacrifice from all who live and work in the Bay watershed. Jurisdictions will not only have to make significant reductions in current loads, but they will need to make additional cuts to address future growth and development over the next 15 years. Implementation strategies for the near-term have been developed for the first of the two-year year milestone periods, and detailed strategies through 2017 are in development through the Phase II WIP process. To reach the long-term load reduction goals, Bay jurisdictions and the federal government will need to consider a wide range of strategies, including some that are receiving little, if any, consideration today. Additionally, Bay part- 125

OCR for page 125
126 NUTRIENT AND SEDIMENT REDUCTION GOALS IN THE CHESAPEAKE BAY ners will need to adapt to future changes (e.g., climate change) that may impact the response of the Bay to reduced loads. In this chapter, the committee takes a broad view of its task to discuss improvements in the development and implementation of strategies to meet the sediment and nutrient reduction goals (Task 6, see Box S-1). The chap- ter covers two main topics. First, the committee discusses future challenges in implementing effective remediation actions, including adapting to future changes in the drivers of Bay degradation and adapting to factors, such as climate change, which may alter the mechanisms of Bay recovery. Addition- ally, the committee discusses the costs associated with nutrient and sediment management actions and the challenge of maintaining political and public will. Second, the committee presents a range of strategies that could be used to help the CBP meet its restoration goals. These strategies encompass a wide range of topics, including practices, policies, funding strategies, and programmatic science management changes that have promise for improv- ing the likelihood of attaining overall restoration goals. CHALLENGES Several cross-cutting issues could affect the pace and likelihood of achieving CBP goals. These challenges include expanding pressures on the Bay, such as population growth and development, changes in agriculture, and climate change. Additional challenges discussed in this section include costs and political and public will. Shifting Drivers of Bay Water Quality and Ecosystem Response The Chesapeake Bay’s ecological integrity and, hence, economic and social value has deteriorated because the ability to prevent excess nutrients and sediment from being discharged into the Bay has not kept pace with the generation of nutrients and sediment from rapid population growth and intensification of agricultural operations. These activities, combined with new economic challenges and impacts of climate change, will continue to challenge Bay restoration efforts. The success of an enhanced focus on water quality in the Bay will be, to a large extent, dependent upon the degree to which current plans (e.g., the total maximum daily load [TMDL]) and future efforts anticipate and respond to these challenges. This section of the report discusses trends in activities that are driving water quality problems in the Bay and the role that additional stressors may play in the ability of the CBP to meet future challenges.

OCR for page 125
127 STRATEGIES FOR MEETING THE GOALS Urban Issues: Population Growth and Development In 2007, the U.S. Environmental Protection Agency (EPA) Inspector General concluded that new development in the Chesapeake Bay watershed had increased nutrient and sediment loads at rates faster than urban res- toration efforts had reduced them (EPA OIG, 2007). This conclusion was reinforced by the CBP 2009 Bay Barometer report, which stated that pol- lution from urban and suburban areas continues to hinder the effectiveness of restoration efforts (CBP, 2010a). Phase 5.3 Watershed Model outputs estimate that total nitrogen loads from urban runoff and septic systems grew by 7.7 percent between 1985 and 2009; total phosphorus loads from urban runoff grew by 5.8 percent and sediment loads by 4.0 percent (see Appendix A). Urban and suburban sources of nutrients and sediment remain the only categories that continue to increase in modeled scenarios. Population growth, development, and wastewater management com- bine to produce the observed impacts of urban and suburban development on water quality. The population of the Chesapeake Bay watershed grew from 8.1 million in 1950 to almost 16 million in 2000 (Claggett, 2007). Population growth estimates suggest that by 2030 the population will exceed 19 million (EPA OIG, 2007). Distribution and patterns of population growth and development across the landscape have a major effect on water quality. Low-density, land-extensive residential development has combined with land-extensive development for other purposes (e.g., business, government), with connect- ing networks of impervious roadways and parking lots. More recently char- acterized as sprawl, this development pattern means that the rate at which open space is converted to support population growth outpaces population growth rates. Between 1990 and 2000, the watershed population increased by 8 percent, but the amount of land converted to development more than doubled. Based on projected population growth and the rate of growth in land development, the area of developed land could increase by more than 60 percent by 2030 (Boesch and Greer, 2003). Sprawl development brings with it significant increases in the amount of impervious surface area, which channels water, nutrients, and sediment to waterways and minimizes the potential for landscapes to absorb them (Claggett, 2007). Between 1990 and 2000 impervious surface area in the Bay watershed increased by 41 percent (Claggett, 2007), and a 2006 study reported that impervious surface accounted for 18 percent of all urban lands in the Bay watershed (Tilley and Slonecker, 2006). Research suggests that stream water quality can be impaired when impervious cover in a watershed exceeds 5-6 percent (Couch and Hamilton, 2002). Population growth and development patterns directly influence nutrient loading from wastewater. Wastewater treatment plants (WWTPs) collect

OCR for page 125
128 NUTRIENT AND SEDIMENT REDUCTION GOALS IN THE CHESAPEAKE BAY and treat wastewater from 75 percent of the households in the watershed, and technology upgrades have substantially reduced nutrient loadings from wastewater to the Bay (see Figures 1-12 and 1-13). However, private septic systems continue to present a challenge. The 2003 Chesapeake Futures report noted that approximately 25 percent of the housing units in the watershed were served by septic systems, contributing an estimated 33 million pounds of nitrogen per year to the watershed. Advanced nitrogen- removing septic designs exist, but they generally are not required for new development (Boesch and Greer, 2003). According to figures produced by the CBP, each new person added in homes built on septic systems results in about 3.6 pounds of nitrogen entering the local stream. By contrast, for homes connected to a state-of-the-art wastewater treatment plant, each new person adds only 1.6 pounds of nitrogen (Blankenship, 2006). For more than 50 years, residential development trends in the United States have been toward larger homes on larger lots at greater distance from urban centers with heavy reliance on septic systems for wastewater management. If population, land development, and reliance on private septic sys- tems continue to grow, the challenges of reducing nutrients and sediment entering the Bay will continue to grow. Simply managing development that comes with population growth may not be sufficient to meet water quality goals. Tom Horton (conservationist) has argued that attention to restricting population growth may be needed: Our environmental impacts are the sum of how many of us there are, and how much each of us demands of the air, water and land. That is our total environmental ‘footprint’. Common sense tells us we can help the Chesapeake Bay and the planet by reducing either per capita impacts, or the number of capitas. It also tells us that if one side of the footprint equation keeps increasing, we will gain that much less from just working the other side (Horton, 2008). Agricultural Issues: Changes in Animal and Crop Agriculture Agriculture is an integral component of the culture, heritage, and econ- omy of the Bay watershed, and as of 2003, agriculture accounted for 13 percent of the region’s gross domestic product (GDP). However, agricul- ture’s share of GDP has steadily declined over the past decades (Boesch and Greer, 2003). Between 2002 and 2007, cropland and farmland acres declined by 10 percent and almost 15 percent, respectively. Furthermore, the type of agriculture being practiced is shifting. Even though the total amount of nutrients and sediment entering the Bay and its tributaries from agricultural sources has decreased since 1985, the agriculture sector has been responsible for a smaller portion of reductions than have point sources, especially municipal wastewater treatment plants. This imbalance

OCR for page 125
129 STRATEGIES FOR MEETING THE GOALS can be explained by the fact that reduction efforts by agriculture tend to be voluntary and incentive-based, whereas efforts by point sources are dictated by regulation. Changes in Animal Agriculture. In 2007, there were 16.8 million people living in the Bay Watershed along with 2.4 million cattle, 1.2 million hogs, and 222 million chickens (U.S. Census of Agriculture, 2007).1 The waste generated by these populations contributed 40 percent of the total nitrogen load to the Bay watershed: 23 percent of the total from human sewage (i.e., septic systems and municipal and industrial wastewater) and 17 percent from animal manure (see Figure 1-6). Although projections for future changes in human population are readily available,2 projections for changes in the animal population are not. However, based on current trends, the number of animal production operations (including dairy) is predicted to decrease as a result of continuing industry consolidation within the Bay watershed. Yet, the number of animals per operation is predicted to continue to increase to meet growing demand, especially from a grow- ing regional market (Mark Dubin, University of Maryland, personal com- munication, 2010). With fewer but larger operations, the total number of animals may well be maintained or even increased. However, the species mix may change. Over the period of 2002 to 2007, cattle, sheep, and swine populations decreased, while the numbers of chickens, horses, and goats increased. Of these, the most notable was the increase in chickens. At this point, formal projections for changes in animal populations are not avail- able from the CBP (Mark Dubin, University of Maryland, personal com- munication, 2010). If the trend towards increased livestock concentration continues, more animal production operations will be classified as point sources, which will bring them under NPDES regulatory requirements and presumably reduce contributions to nutrient loads. Agricultural Production and Land-Use Changes. Shifts in agricultural pro- duction and land use often occur because of external pressures, and these changes have implications for nutrient management in the Bay watershed. For instance, the drive for biofuel production to provide a greater share of consumed energy, often required by law,3 could lead to increased nutrient loading from agricultural lands. Between 2005 and 2010, corn acreage in 1 Note that the 2007 Census of Agriculture numbers reported are for mid-atlantic subwatersheds that drain to the Bay. The human population is from the CBP, available at http://www.chesapeakebay.net/status_population.aspx?menuitem=19794. 2 See http://www.chesapeakebay.net/populationgrowth.aspx?menuitem=14669. 3 For example, the American Recovery and Reinvestment Act of 2009 required 12.5 billion gallons of biofuel (primarily ethanol) be mixed with gasoline by 2012.

OCR for page 125
130 NUTRIENT AND SEDIMENT REDUCTION GOALS IN THE CHESAPEAKE BAY Bay watershed states increased by 11 percent, mostly on land removed from soybean production, the Conservation Reserve Program, and pastureland (USDA National Agricultural Statistics Service, 2010). The potential for nitrogen and phosphorus loss from corn production is greater than most other land uses (see Box 5-1). Additionally, the incorporation of dry distiller’s grain (DDG), a by- product of ethanol production, into beef and dairy cattle rations could erode progress in managing nitrogen and particularly phosphorus in animal feed (to reduce nutrients in manure). Using DDGs as a feed ration alterna- tive is likely to increase because of its ready availability and low cost relative to corn grain prices. However, the phosphorus content of DDGs (0.8-0.9 percent phosphorus) is about three times that of corn, which makes it dif- BOX 5-1 Shifting Nutrient Loads from Agricultural Land Use Changes Corn is an inherently inefficient nitrogen user; 40 to 60 percent of ni- trogen applied generally is not taken up by the crop, and nitrogen loads to downstream aquatic ecosystems from corn-dominated landscapes are typically 25 to 45 lb nitrogen ac-1 yr-1 (Balkcom et al., 2003; Randall et al., 2003). Nitrogen losses to aquatic systems from soybeans average 18-35 lbs nitrogen ac-1 yr-1 (CBP, 2006). Similarly, average phosphorus losses in runoff from corn (3-18 lbs ac-1 yr-1) tend to be greater than from soybeans (1-10 lbs ac-1 yr1) (Carpenter et al., 1998; Kimmell et al., 2001; Sharpley and Rekolainen, 1997). The loss of phosphorus from perennials and hay crops (0.2-1 lb ac-1 yr-1) is generally less than from annuals because runoff volumes are lower and crop phosphorus requirements are smaller, so smaller amounts of fertilizer or manure are applied (Sharpley et al., 2001; Smith et al., 1992). Further, water-quality model simulations of converting Conservation Reserve Program acre- age or perennial grasses to cropland confirm that delivered nitrogen and phosphorus loads increase by more than double the percentage land area converted (Mankin et al., 1999, 2003). Assuming fertilizer applica- tion rates remained constant, the estimated 0.25 million acre increase in corn acreage (0.1 million ha) over the past five years in the Chesapeake Bay Watershed is projected to have increased annual nutrient loads by 5 million lbs nitrogen and 2 million lbs phosphorus (Table 5.1).

OCR for page 125
131 STRATEGIES FOR MEETING THE GOALS ficult to use such materials at more than 15 percent of animal feed rations without exceeding dietary phosphorus recommendations (Lawrence, 2006; NRC, 2000). The inclusion of DDGs in rations exceeding recommended rates will increase the phosphorus content of manure (Baxter et al., 2003; Maguire et al., 2004; Wu et al., 2001) and, if the manure is land-applied, increase the potential for phosphorus loss in runoff (Ebeling et al., 2002; Maguire et al., 2007; Sharpley et al., 2005). Climate Change Climate change is likely to affect the Bay’s response to nutrient and sediment management controls. However, uncertainty exists in predicting TABLE 5-1 Estimated Increase in Nutrient Export in Farm Runoff from Growing an Additional 0.25 Million Acres of Corn in the Chesapeake Bay Watershed Nitrogen Export in Phosphorus Export in Runoff Runoff Land Acreage Shift to Area Average Change Average Change (103 ac) (lbs ac–1) (103 lbs) (lbs ac-1) (103 lbs) Support Ethanol New corn acres 250 35 +8,750 11 +2,750 Converted from 110 27 –2,970 6 –660 soybeansa Converted from 12 4 –48 0.2 –2 CRP landa Converted from 125 5 -625 0.6 –75 idle, pasture or hay landa Estimated increased +5,107 +2,013 nutrient export in runoffb aNutrient export of nitrogen and phosphorus if land had remained in soybeans, Conservation Reserve Program, idle, pasture, or hay land. bIncrease in nitrogen and phosphorus export in runoff estimated as that occurring from additional corn acres minus the runoff that would have occurred from the original land use prior to conversion to corn. SOURCE: Adapted from Simpson et al. (2008).

OCR for page 125
132 NUTRIENT AND SEDIMENT REDUCTION GOALS IN THE CHESAPEAKE BAY BOX 5-2 Historical Climate Changes and the Effect on Hypoxia The relationship between spring nitrate loading from the Susque- hanna River (a proxy for total nitrogen loading to the Bay) and the result- ing summer time anoxic water was examined by Hagy et al. (2004) and is shown in Figure 5-1. There appears to be a change in the anoxia’s response to nitrogen loading. The anoxia that developed during the latter years (1980-2001) was significantly greater than that which developed during the early years (1950-1979) for the same winter-spring loading. For example, a January-May loading of 20 gigagrams (Gg), resulted in an anoxic volume of approximately 1 km3 in the early years and perhaps 3 km3 in the latter years. There is significant scatter in these data, and the loading and anoxic volume estimates in the early years are less reliable than those subsequent to 1985 when more intensive monitoring became available. This striking result has generated a number of hypotheses, including the idea that a “regime shift” has occurred in the biology (Petersen et al., 2008). More mechanistic hypotheses have been advanced, but all are associated with changes that are related to climate variation. Suspected mechanisms include wind direction (Scully, 2010a,b); increase in water temperature, decrease in oyster abundance and associated filtration capacity, and less efficient nitrification-denitrification (Kemp et al., 2009); and decreased mixing of waters and increases in early summer stratifica- tion (Murphy et al., 2011). In particular, Murphy et al. (2011) have sug- gested that the decreased mixing of waters and increased early-summer stratification may relate to both an observed shift in the predominant wind direction over the Bay (Scully, 2010a) and to observed increases of Bay salinity levels, which have in turn been related to sea level rise (Hilton et al., 2008). climate change effects on the forcing functions to the Bay (e.g., magnitudes and timing of rainfall and runoff, range and patterns of temperature varia- tion, influence of storm activity) and how the Bay’s physical, chemical, and biological systems will respond. Nevertheless, attempts have been made to quantify the possibilities, using models and professional judgment. Najjar et al. (2010) published a comprehensive examination of the potential responses of the Bay to climate change and concluded that “likely changes” include increases in precipitation amount and intensity, salinity variability, harmful algae, hypoxia, and coastal flooding. Annual mean temperatures in the Bay Watershed are projected to increase by 1ºC during

OCR for page 125
133 STRATEGIES FOR MEETING THE GOALS FIGURE 5-1 Midsummer volume of anoxic bottom water vs. winter-spring Figure 5-1.eps nitrate loading from Susquehanna River for earlier years (1950-1979, bitmap solid line, filled circles) and for later years (1980-2001, dashed line, open circles). SOURCE: Kemp et al. (2005), modified from Hagy et al. (2004). the next 30 years and perhaps by 7ºC by the end of this century. Najjar et al. (2010) concluded: “Climate change alone will cause the Bay to function very differently in the future.” Such changes include altered interactions among trophic levels and a reduction in eelgrass, the dominant species of underwater grasses in the Bay. Even small changes in water temperature are projected to have significant impacts on fishery resources. Climate changes during the past 50 years also appear to be affecting the extent of Bay hypoxia that can be detected in observational data (Box 5-2). Climatic variations can dramatically change the Bay’s response to nutrient manage- ment actions. To avert overly optimistic expectations, and the associated

OCR for page 125
134 NUTRIENT AND SEDIMENT REDUCTION GOALS IN THE CHESAPEAKE BAY disappointment from achieving less than forecasted results, a systematic investigation should be initiated. Coupling the currently available models, validated by hindcasting historical data, with the available climate change scenarios would be a first step. Costs Meeting the overall cost of Bay management is a key challenge facing the CBP. In October 2004, the CBP’s Blue Ribbon Finance Panel consid- ered the entire 64,000 square mile watershed and estimated total water quality restoration costs at $28 billion (or $32 billion in 2010 dollars).4 This is equivalent to approximately $1,900 (in 2010 dollars) for each of the 16.8 million residents in the Bay watershed. The recent release of the watershed implementation plans (WIPs) has generated additional concerns about the costs of implementation (EPA, 2010f). For example, Maryland estimates costs to residents, businesses, and taxpayers of meeting the goals of its Phase I WIP at $13-15 billion (MDE et al., 2010). Virginia estimates costs in that state of implementing its Phase I WIP will exceed $7 billion (VA DNR, 2010). Undoubtedly, the costs reported in these and other docu- ments are rough estimates at best, but their magnitude is indicative of the financial challenges posed. Costs beyond those included in financial calculations are also possible. For example, restrictions on land-use changes and limits on growth could be manifested over time in higher housing costs. Efforts to reduce airborne nutrient sources could raise the cost of energy generation or transportation. Lifestyle changes also may be required, such as restrictions on residential and commercial landscaping (e.g., restricted fertilizer applications) and greater reliance on public transportation. However, such lifestyle changes could offer economic benefits, such as reduced day-to-day cost of living for individuals and reduced emissions of greenhouse gases. Also, many BMPs may offer broader benefits than just those targeted; for example, reduc- ing stormwater runoff volume to protect water quality may reduce flood damages. The costs of nutrient and sediment reduction are unlikely to be evenly distributed. Even if nutrient and sediment reductions are distributed across the Bay jurisdictions based upon their relative contributions, the shares of the overall cost borne by any jurisdiction’s residents, businesses, and taxpayers are likely to vary depending upon the specific sources within the jurisdiction’s boundaries and the location of the jurisdiction within the watershed. Much of the public cost will be absorbed by taxpayers as local governments deal with upgrades to wastewater treatment plants and 4 See http://archive.chesapeakebay.net/blueribbon.htm.

OCR for page 125
135 STRATEGIES FOR MEETING THE GOALS stormwater management, and higher taxes and fees are always contentious. Distribution of costs across regulated and unregulated sources will differ. All states have indicated that they will rely upon federal funds to cover a substantial portion of implementation costs. In light of other federal bud- getary pressures, sufficient federal assistance is unlikely. Costs to Agriculture The costs to agriculture of implementing BMPs to further reduce nutri- ents and sediments will be a function of the mix of land management requirements adopted by states, financial assistance from federal, state, and local governments, and the financial benefits that may offset some or all of the costs incurred by farmers’ groups. A substantial body of research indi- cates that many agricultural practices that reduce nutrient and sediment loss from farms can offer economic benefits and sometimes provide competitive gains at the farm level (NRC, 2010). However, some practices may impose significant on-farm costs that are not recovered. Agricultural producers are not able to set the prices they receive for their products and, as a result, are not able to make adjustments to cover additional costs of implementing BMPs. Farmers groups have questioned whether agriculture can bear the costs of additional BMPs (American Farm Bureau, 2010). Estimates of costs to agriculture vary widely, and how the relative on-farm costs and benefits of individual BMPs are accounted for in these estimates is not clear. In 2005, the CBP estimated the cost of implement- ing agricultural portions of Bay cleanup strategies at about $700 million a year, with only $188 million in conservation funding provided each year by the 2008 Farm Bill (Blankenship, 2008). More recent estimates suggest that the costs to agriculture could be even higher, and the future availabil- ity of federal and state subsidies is uncertain. Without doubt, the costs of reducing agricultural sources of nutrients and sediment will be very high. Deciding how and among whom the costs will be distributed represents a substantial challenge. Costs in Urban Areas Efforts to control nutrients and sediments in the Bay watershed have had, and will continue to have, significant effects on the way municipalities and industries manage their land, wastewater, development, and redevelop- ment. The seven Bay jurisdictions have identified ambitious plans neces- sary to meeting the wasteload and load allocations required by the TMDL (EPA, 2010a). Although they do not fully articulate the potential sector- specific costs associated with TMDL compliance, together with information from the 2008 Clean Watersheds Needs Survey (EPA, 2010g) they provide

OCR for page 125
156 NUTRIENT AND SEDIMENT REDUCTION GOALS IN THE CHESAPEAKE BAY Demand for nutrient credits to meet urban nonpoint-source limits may be limited because emerging stormwater programs are requiring develop- ers to exhaust feasible on-site controls before purchasing nutrient credits (Stephenson and Shabman, 2010). New and expanding point sources are more likely than existing point sources to seek out nutrient credits to meet offset requirements (Selman et al., 2010; Stephenson et al., 2010). Even then, however, point sources may be hesitant to seek nutrient credits from nonpoint sources. Stephenson et al. (2010) determined, for example, that offsetting a discharge expansion of 1 million gallons per day (MGD)12 under Virginia’s nutrient trading program would require the application of continuous no-till on 10,000-25,000 acres of cropland. With average farm sizes ranging from 100 to 400 acres across Virginia’s four river basins, offsetting even a 1 MGD expansion would likely involve contracting with several dozen farm operations—a high transaction cost proposition for any individual point source. Taken together, these challenges suggest that nutrient offset or credit trading is not a panacea for reaching nutrient reduction goals at lower cost. Removal of institutional constraints that restrict supply and demand at federal and state levels will be required if states are to implement effective trading programs (King and Kuch, 2003; Shabman and Stephenson, 2007). Funding Urban Stormwater Management Funding urban stormwater management is fraught with challenges but some innovative approaches are being considered. Increasingly, local entities are providing incentives to promote adoption of stormwater BMPs by homeowners and businesses, including LID techniques and other green infrastructure approaches (EPA, 2010j). Incentives are not always mon- etary; other forms of encouragement to promote BMP implementation include development incentives offered to developers during the process of applying for development permits, such as zoning upgrades, expedited permitting, and reduced regulatory requirements. Awards and recognition programs can also encourage homeowner and commercial efforts (EPA, 2010j). Supplementary granting programs, such as the federal Section 319 nonpoint source program, can help to defray implementation costs for unregulated stormwater activities, but at about $200 million/year nation- ally, available funds will not provide for all of the TMDL’s unregulated urban runoff control requirements. 12 For comparison, the Alexandria Sanitation Authority in Alexandria (Fairfax County), Virginia, processes on average 54 million gallons of wastewater per day and serves about 350,000 people in the City of Alexandria and part of Fairfax County (see http://www.alexsan. com/).

OCR for page 125
157 STRATEGIES FOR MEETING THE GOALS Section 319 funds cannot be used to meet requirements of the MS4 or other stormwater permits. To meet MS4 stormwater quantity and quality requirements, some municipalities have instituted stormwater or develop- ment fees that are assessed based on type of land use and area of impervious surface and increasingly administered through stormwater utilities (EPA, 2008c). A stormwater utility (called a stormwater authority in Pennsylvania) is a mechanism to fund the cost of municipal services directly related to the control and treatment of stormwater. A stormwater utility will operate similarly as an electric or water utility. The utility will be administered and funded separately from the revenues in the general fund, ensuring a dedicated revenue source for the expense of stormwater management. (EPA, 2008c) Generally, stormwater utilities collect fees from property owners based on the amount of stormwater runoff generated. Utilities commonly use an “equivalent residential unit” to establish fee rates, based on: (1) the amount of impervious cover in the parcel, regardless of size; (2) the inten- sity of development (i.e., the percentage of impervious cover relative to the entire parcel’s size); or (3) an equivalent hydraulic area, based on the combined impact of impervious and pervious cover within a parcel (EPA, 2008c). Based on a Connecticut study, Fuss and O’Neill (2010b) concluded that stormwater utilities could effectively support implementation of LID by providing subsidies for LID demonstrations, funding for operation and maintenance, technical assistance in LID design and installation, and fund- ing for retrofits for water quality improvements. The City of Portland, Oregon, instituted a Clean River Rewards Program that incentivizes par- ticipation by providing discounts on stormwater bills of homeowners who implement particular practices to “contain the rain” (City of Portland, 2006). Nationally, in 2009, stormwater utility fees varied widely, ranging from $8 to $160 per year for a single family home with an average fannual ee of $44 (Fuss and O’Neill, 2010b). Funding Monitoring Strategies As described in Chapter 4, monitoring and evaluation of reported ambient stream water quality, particularly at a small watershed scale, is a critical part of understanding the field-scale effectiveness and timescales of response following BMP implementation. Identifying sufficient funds to support an ambient monitoring program capable of detecting potential changes in local water quality in response to BMP implementation can be difficult for individual private entities, small municipalities, and even states.

OCR for page 125
158 NUTRIENT AND SEDIMENT REDUCTION GOALS IN THE CHESAPEAKE BAY NRCS has recently developed an interim Conservation Practice Stan- dard (#799) to encourage monitoring and evaluation of BMP effectiveness by private landowners. It is being made available on a pilot basis, with 75 percent cost-sharing support through the NRCS Environmental Qual- ity Incentives Program (EQIP), in a number of states that are part of the Mississippi River Basin Healthy Watershed Initiative (MRBI). The most landowner interest, to date, has been in Missouri, where state funds were used to cover the landowners’ portion of the costs and cover the technical expertise needed to implement monitoring protocols. However, overall, landowner participation has been limited (Thomas Christensen, NRCS, personal communication, 2011). No plans have been made to extend the pilot program to the Bay watershed states, although such an arrangement could be promising, particularly if coupled with targeted small-watershed monitoring initiatives that would complement the landowners’ edge-of-field monitoring. If applied in the Bay watershed, collaboration between land- owners and state or federal agency representatives or university scientists would be needed to develop monitoring plans and to install equipment. One example of a successful local government collaboration to pro- vide financial support for ambient water quality monitoring is the South- ern California Stormwater Monitoring Coalition (SMC). The SMC was formed in 2001 as part of the Southern California Coastal Water Research Project (SCCWRP), a collaborative public agency created in 1969 to con- duct coastal environmental monitoring and research.13 The SMC was the result of a cooperative agreement among the Phase I municipal stormwater NPDES lead permittees, the NPDES regulatory agencies in Southern Cali- fornia, and SCCWRP. 14 The SMC members agreed, with EPA cooperation, that NPDES compliance monitoring schedules would be adjusted periodi- cally to make available funding that may be appropriately re-directed to support cooperative ambient monitoring and reporting efforts. To enhance support for CBP monitoring efforts (and adaptive manage- ment), local and regional governments and industries within Bay subwa- tersheds may wish to consider similar cooperative efforts. One option is re-directing some funds currently used for individual NPDES compliance monitoring toward an established localized ambient monitoring program or a collaborative effort between different monitoring programs using standardized data collection approaches to allow data collation and com- parison. Similarly, some percentage of federal funds provided to agricultural and other landowners to cost-share BMP implementation could be directed to existing or collaborative ambient water quality monitoring programs specifically designed to detect potential changes in stream water quality 13 See http://www.sccwrp.org/. 14 See http://www.socalsmc.org/.

OCR for page 125
159 STRATEGIES FOR MEETING THE GOALS associated with BMP implementation. As noted in Chapter 4, such moni- toring programs would need to be carefully targeted toward addressing specific uncertainties related to practice effectiveness and Bay response if the monitoring is to support adaptive management. Establishing a Chesapeake Bay Modeling Laboratory The final strategy that the committee presents in this chapter addresses improving the scientific and modeling support for the CBP to increase the likelihood that the program will meet its ultimate goal—recovery of the Chesapeake Bay. The committee was not asked to—and did not—review the models. However, the models that collectively make up the Chesapeake Bay Model (i.e., the Airshed Model, the Watershed Model, and the Bay Model; see Box 1-1) are central to the proper allocation of restoration resources, evaluation and planning, and the ongoing adaptive management of the Bay in a changing future. The models have been used to estimate the loading reductions of nitrogen, phosphorus, and sediment necessary to achieve water quality and living resources objectives (i.e., the TMDLs). Models are used to estimate the effect of BMPs on loading reductions to the Bay, thereby providing essential information for planning and evaluat- ing implementation strategies. Models are central to forecasting the Bay’s response to future loading reductions and to system perturbations, such as climate change and annual differences in precipitation to the watershed. Thus, models are essential to the success of the CBP. As a consequence, they need to be continuously evaluated as new data are collected, updated as mechanistic understanding increases, and scrutinized for inconsistencies and possible computational and scientific inaccuracies. The models presently reside in two locations: the Watershed Model at the EPA Chesapeake Bay Program Office and the Bay Model at the U.S. Army Waterways Experiment Station. Only a few technical professionals are completely familiar with the details of the models, their history of devel- opment, and the long series of changes and improvements that have been made over the 25 years of development. This is a fragile and precarious situation. Although the codes for both models are publicly available at the Chesapeake Community Modeling Program (CCMP), they are complex and using them would pose a challenge for even experienced modelers. There is no active community involved in exercising these models. The documenta- tion that exists for the models is no substitute for a community of scien- tists and engineers who understand their inner workings and have actually used the models. This is in sharp contrast to other modeling communities, for example the climate modeling community, in which there are multiple modeling efforts, some of which are centered in national laboratories, and for which comparisons of the various models is a common practice (e.g.,

OCR for page 125
160 NUTRIENT AND SEDIMENT REDUCTION GOALS IN THE CHESAPEAKE BAY Macadam et al., 2010). The Chesapeake Bay hydrodynamic modeling com- munity shares some of these characteristics, but the Airshed, Watershed, and Bay Models do not. The CCMP has held and continues to hold open and regular meetings during which progress in building, calibrating, and using the models is discussed. However, these models are not used by academics for research investigating the mechanisms that control ecological responses of the Bay. The number of persons at present who can actually make computations is limited to a very few, and there are just two senior scientists among the CBP modeling group—one each for the Watershed Model and Bay Model. Their time in the past has been completely committed (actually over-committed) to the tasks associated with building, calibrating, and using the models to fulfill various management requirements, most recently the development of the TMDL. As a consequence time has been unavailable for the critical cooperative work with the scientific community that would enable a much wider familiarity with and acceptance of these models. Credibility of these models among the scientific, engineering, and management communities that are concerned with understanding, man- aging, and protecting Bay water quality is critically important. A recent analysis by LimnoTech (2010), which used a USDA model designed to simulate changes in nutrient loading resulting from conservation prac- tices on crop land in the Bay watershed, reported discrepancies with the CBP Watershed Model, including the amount of agricultural nutrients that reach the Bay. The LimnoTech report has fueled a growing back- lash against the Bay TMDL and spurred several members of the House Agriculture Committee to conclude that the CBP models used to develop the TMDL are “fatally flawed” (Blankenship, 2011). Although this NRC committee did not analyze the LimnoTech report or the discrepancies in the models, this issue highlights how technical concerns regarding the CBP models can undermine support for the CBP goals and strategies, the details of which are developed and evaluated using the models. Because the models are not widely used outside the CBP, they lack credibility with the broader scientific community that would result from a history of independent applications. Thus, the academic community has largely been unable to weigh in on this recent controversy, although the CBP Scientific and Technical Advisory Committee is planning an independent review of the LimnoTech report. Considering the magnitude of the remediation costs and the value of the Bay resource, this situation needs to be addressed. The atmospheric and oceanographic communities have national laboratories (i.e., the National Center for Atmospheric Research [NCAR] and the Geophysical Fluid Dynamics Laboratory [GFDL], respectively) that are centers for the devel- opment of atmospheric and oceanic circulation models and more recently

OCR for page 125
161 STRATEGIES FOR MEETING THE GOALS the climate models that are used to forecast the possible consequences of various climate-related control measures. A similar laboratory entrusted with the stewardship of the Chesapeake Bay models could be developed for the CBP and charged with evaluating monitoring data and uncertainty in model simulations, improving the predictive skill of the models, and continuously seeking model improvements to accommodate new scientific understanding of the system. Such a laboratory could also be central in designing and improving the CBP monitoring programs, evaluating the consequences of adaptive management experiments, helping to understand where and why pollution controls did not perform as effectively as planned, identifying science gaps, and evaluating the consequences of climate change. Finally, it would be the place where sound technical analysis and advice could be obtained by managers for the inevitable changes that will be neces- sary as nutrient and sediment reductions are implemented and the resulting responses of the Bay ecosystem are evaluated. When specific issues are raised, smaller scale models built to answer specific questions could be implemented and/or developed as part of the laboratory’s research. A lab would have the personnel to do the develop- ment and would not be wed to one watershed model or one Bay model. A laboratory could also facilitate improvements to the models to support the 2017 re-evaluation of the TMDL and the WIPs. Involvement of the academic community in a laboratory is vitally important. The flow of ideas among the policy, management, and academic communities is a crucial part of the continuing development of state-of-the- art models and understanding. Faculty could form research associations with lab personnel, and lab personnel could have appointments in aca- demic departments. The success of NCAR and GFDL is due in part to their proximity to research universities. Recognition of the need for improved integration of the academic community and the CBP modeling program is not new.15 What is new is the recommendation that an actual laboratory be established that fulfills the functions listed above and is more than just a virtual association of collaborating individuals. Instead, the committee envi- sions a modeling laboratory as a physical location, following the examples of NCAR and GFDL. The actual institutional sponsorship of the laboratory, its relation- ship to management agencies, and the makeup of the research staff would require serious deliberation. There are tradeoffs to be considered. A lab that is too “academic” might not be responsive to immediate needs. A focus that is too “operational” would merely continue the current situation where scientific functions are not given sufficient priority. A lab with too many varied responsibilities would dilute the effort from a focus on modeling. 15 See http://ches.communitymodeling.org/documentation/pdf/ModelPreamble.PDF.

OCR for page 125
162 NUTRIENT AND SEDIMENT REDUCTION GOALS IN THE CHESAPEAKE BAY Surveying similar labs and their successes and failures would be a useful exercise. The NOAA Great Lakes Environmental Research Laboratory, the EPA research labs, and the Everglades Interagency Modeling Center are additional examples worth examining. An important component of the work of a modeling laboratory would be the integration of monitoring with modeling efforts, as recommended in Chapter 4. A laboratory could contribute to designing future data collec- tion efforts, relocating sampling stations where the uncertainty of the Bay response is largest, locating monitoring stations in the watershed where loading reductions are predicted to have the largest observable changes, and supporting adaptive management experiments. Because monitoring is costly, any improvement in existing monitoring efficiency could make resources available for other needs. Integrated modeling and monitoring is also needed to help determine whether CBP management actions are working as anticipated (STAC, 1997, 2005), and this requires models that can accurately simulate the time scales of BMP response and nutrient storage and transport. Time lags between land-based BMP implementation in the Bay watershed and full responses in nutrient and sediment loadings (see Box 1-3), however, remain poorly understood and have not been quantified. The existing models incorporate some of the necessary mechanisms, but others are clearly missing or are not well calibrated. For example, the Bay Model includes a sediment model that is capable of calculating lag times associated with the degradation of organic nitrogen and the storage of inorganic phosphorus (see Figure 1-2), but the land simulation in the Watershed Model has no routing from the land surface to the streams to account for nutrient storage in soils, nor a sediment model for the stream beds, and thus no associated lag times. BMPs are, instead, modeled as instantaneous and permanent pollutant reductions. Also, the groundwater lag in the Watershed Model is virtually nonexistent (hours to days). To incorporate this time lag would require coupling to a separate groundwater model to simulate lags based on groundwater flow (G. Shenk, CBPO, personal communication, 2011). Increases in nitrogen in the Choptank River, as described by Hirsch et al. (2010; see Figure 1-12b) are representative of groundwater and surface water interactions that are not simulated well by the Watershed Model. Through a Chesapeake Bay modeling laboratory, disciplinary scientists and engineers and modelers could collaborate to quantify lag times in the Bay watershed and translate the phenomena into operational calculation frameworks. Additional intensive monitoring in small watersheds could be conducted to quantify the time scales of contributing mechanisms. Model hindcasting could be used to analyze whether existing models are capable of accurately forecasting the course of Bay remediation and elucidate the

OCR for page 125
163 STRATEGIES FOR MEETING THE GOALS strengths and weaknesses of the present formulations.16 If deemed neces- sary, additional smaller-scale models could be developed to simulate the time frames of BMP responses. This research would be essential to respond to concerns that management plans are not performing as expected and to support the analysis of progress. Additionally, if significant lag times between implementation of land-based BMPs and nutrient loads reduc- tions are determined, the research could help maintain public support for continued efforts and investments in Bay recovery. CONCLUSIONS Reaching the long-term CBP nutrient and sediment reduction goals will require substantial commitment from each of the Bay jurisdictions and likely some level of sacrifice from all who live and work in the watershed. Jurisdictions not only need to significantly reduce current loads, but they will need to take additional actions to address future growth and develop- ment over the next 15 years. Additionally, the Bay partners will need to adapt to future changes (e.g., climate change, changing agricultural prac- tices) that may further impact water quality and ecosystem responses to planned implementation strategies. To reach the long-term load reduction goals, Bay jurisdictions and the federal government will need to prepare for the challenges ahead and consider a wide range of possible strategies, including some that are receiving little, if any, consideration today. Success in meeting CBP goals will require careful attention to the con- sequences of future population levels, development patterns, agricultural production systems, and changing climate dynamics in the Bay Watershed. Nutrient and sediment management efforts are taking place in the con- text of a quickly changing landscape and uncertain outcomes that could significantly affect the strategies needed to attain the TMDL goals. For example, an increase in the concentration of livestock or dairy animals near processing and distribution centers would mean a greater concentration of manure nutrients in these areas than has existed in the past. Additionally, Bay jurisdictions may need to adjust future milestone efforts to larger than anticipated population and more intensive land-use development scenarios, as well as climate change influences. Further and continued study of future scenarios is warranted to help Bay partners adapt to a changing future. Helping the public understand lag times and uncertainties associated with water quality improvements and developing program strategies to 16 For example, starting with 1950 simulations, the CBP could calculate the relationship between loadings to the bay and the water quality responses from 1950 to the present. The computations can then be verified against observations to better understand the lag times incorporated in the model.

OCR for page 125
164 NUTRIENT AND SEDIMENT REDUCTION GOALS IN THE CHESAPEAKE BAY account for them are vital to sustaining public support for the program, especially if near-term Bay response does not meet expectations. Although the science and policy communities generally recognize the uncertainties inherent in water quality modeling, load projections, and practice effective- ness and expect that water quality successes will lag implementation, the same may not be true of the broader public. If the public expects visible, tangible evidence of local and Bay water quality improvements in fairly short order, they will almost certainly become frustrated. In the absence of a concerted effort to engage Bay residents in a conversation about the dynamics of the Bay and how and when improvements can be expected, CBP partners should anticipate and be prepared to respond to an impatient or disillusioned public. By developing small watershed-scale monitoring efforts that highlight local-scale improvements and associated time lags in water quality as they occur, the CBP can better understand and inform the public about anticipated responses to, and expectations for, nutrient control measures. The committee identified potential strategies that could be used by the CBP partners to help meet their long-term goals for nutrient and sediment reduction and ultimately Bay recovery. The committee did not attempt to identify every possible strategy that could be implemented but instead focused on approaches that are not being implemented to their full potential or that may have substantial, unrealized potential in the Bay watershed. Because many of these strategies have policy or societal implications that could not be fully evaluated by the committee, the strategies are not pri- oritized but are offered to encourage further consideration and exploration among the CBP partners and stakeholders. Examples include: Agricultural Strategies • Improved and innovative manure management. Possible strategies include expanded CAFO permitting programs, guidelines and/or regula- tions to control the timing and rates of manure application, innovative manure application methods, transport of manure to watersheds with the nutrient carrying capacity to accept it, alternative uses (e.g., bioenergy production), animal nutrition management to reduce nutrient loading, and limits on the extent of animal operations based on the nutrient carrying capacity of the watershed. • Incentive-based approaches and alternative regulatory models. Several approaches have been used successfully elsewhere to increase the use of agricultural BMPs for the purpose of improving water quality. Florida developed a voluntary, incentive-based BMP program that provides regulatory relief in exchange for BMP implementation, maintenance, and reporting. Denmark’s nutrient management program provides an alterna-

OCR for page 125
165 STRATEGIES FOR MEETING THE GOALS tive model that couples agricultural regulatory requirements with incentives and has resulted in large reductions in nutrient surpluses. The CBP could facilitate an analysis of the costs and potential effectiveness of various incentive-based and regulatory alternatives. Urban Strategies • Regulatory models that address stormwater, growth and develop- ment, and residential fertilizer use. Watershed-based permitting for urban stormwater can lead to cost savings if a consortium of permittees chooses to organize to distribute pollutant load allocations and contribute to monitor- ing and tracking efforts in their local or regional watersheds. Restrictions on nitrogen and phosphorus residential fertilizer application are cost-effective methods of nutrient load management in urban and suburban areas. Com- munities could also adopt regulations to restrict land-use changes that would increase nutrient loads from stormwater runoff or cap wastewater treatment plant discharges at current levels, requiring offsets for any future increases. • Enhanced individual responsibility. Enhancing individual respon- sibilities, either through education and incentives or through regulations, can also contribute to the success of Bay restoration and to water quality improvements. Examples of actions that individuals can take to improve water quality include increasing application of low-impact design and resi- dential stormwater controls, changing residential landscape management, maintaining and upgrading septic systems, and changing diets. Cross-cutting Strategies • Additional air pollution controls. Although the Chesapeake Bay has realized substantial benefits from the Clean Air Act, the atmosphere remains a major source of nitrogen entering the Bay. More stringent con- trols on nitrogen emissions from all sources, including NOx and agricultural ammonia emissions, will benefit both the Bay and the people who reside in its watershed. Innovative funding models will be needed to address the expected costs of meeting Bay water quality goals. Targeting agricultural BMP cost-share programs is not always politically popular, but it can produce greater reduc- tions at lower cost than will distributing resources broadly with little atten- tion to water quality impacts. Although nutrient trading among point and nonpoint sources is often cited as a mechanism to reach nutrient reduction goals at lower cost, its potential for reducing costs is limited. Stormwater utilities offer a viable funding mechanism to support stormwater manage- ment efforts of municipalities. Funding for monitoring will also be needed,

OCR for page 125
166 NUTRIENT AND SEDIMENT REDUCTION GOALS IN THE CHESAPEAKE BAY and successful regional monitoring cooperatives in other parts of the United States may be useful models. Establishing a Chesapeake Bay modeling laboratory would ensure that the CBP would have access to a suite of models that are astate-of-the-art and could be used to build credibility with the scientific, engineering, and management communities. The CBP relies heavily on models for setting goals and evaluating nutrient control strategies; thus, the models are essen- tial management tools that merit substantial investment to ensure that they can fulfill present and future needs. Currently, only a few technical profes- sionals are fully knowledgeable of the details of the models and their devel- opment. The models are not widely used outside the CBP and, therefore, are unfamiliar to the broader scientific community. Credibility of the models is essential if the CBP goals and strategies are to be accepted and have widespread support. A Chesapeake Bay modeling laboratory would bring together academic scientists and engineers with CBP modelers to examine various competing models with similar objectives and work to enhance the quality of the simulations. An important component of the work of a modeling laboratory would be the integration of monitoring with modeling efforts. Joint research investigations focused on evaluating the success of the Bay recovery strategies could be centered in the laboratory, such as studies on the role of lag times in the observed pollutant loads and Bay responses. A close association with a research university would bring both critical review and new ideas. A laboratory could also facilitate improvements to the models to support the 2017 re-evaluation of the TMDL and the WIPs.