Natural Resources

Water Quality

Virginia river falls in the autumn

Water Quality

Good water quality means much more than having a nice place to swim or even potable water to drink. Virginia's streams, rivers, bays and coastal estuaries perform a long list of important functions that are critical to the state's economic and environmental health.

Why is This Important?

Clean water is a habitat for economically and ecologically important species; it is also necessary for the daily health and hygiene of every Virginian. Clean water is also essential to industrial and agricultural production and is a critical resource for the fishing and tourism industries. Dirty water must be cleaned before being considered fit for most uses, incurring high costs for both public and private enterprise.

How is Virginia Doing?

The Chesapeake Bay: Pollutants

The Chesapeake Bay is a particularly important water resource for Virginia, yet it has been in a beleaguered state for decades. The bay is plagued by agricultural and suburban runoff loading phosphorus and nitrogen into the water, which feed the algae and create dead zones that kill marine life. Since 1980, population along the watershed has grown by over 5 million, increasing the number of paved surfaces that feed polluted runoff into the Bay from parking lots, highways, and commercial and residential buildings. 

Virginia has agreed to substantially reduce its contribution to the nitrogen, phosphorous, and sediment loads in the bay by 2025 by following strategies outlined in a recently adopted Watershed Implementation Plan. Already, nitrogen pollution from Virginia has fallen from a total of 68.1 million pounds in 2009 to 58.7 million pounds in 2015; discharges of phosphorus have also dropped -- from 8.7 million pounds in 2009 to 6.5 million pounds in 2015.

Discharges into the Chesapeake Bay (pounds per year)
Target 2017
Target 2025
Nitrogen 68,127,540 60,860,114 59,023,893 58,763,363 58,803,790 52,587,957
Phosphorus 8,671,812 7,660,214 6,623,916 6,520,982 7,309,951 6,402,043
Total Suspended  Solids 3.7 trillion 3.58 trillion 3.66 trillion 3.57 trillion 3.4 trillion 3.25 trillion
Source: Virginia Department of Environmental Quality, Watershed Implementation Plans

Sediment pollution targets are also included in the Watershed Implementation Plan; in 2015, 3.57 trillion pounds of sediment made their way from Virginia sources into the Chesapeake Bay, a welcome drop from the previous year's 3.66 trillion. The plan goal is to reduce sediment totals to 3.25 trillion pounds by 2025. It is hoped that progress toward all plan goals will further improve as point source regulations are fully implemented, non-point source funding increases, and use of best management practices expands.

The Chesapeake Bay: Restoration

Acres of Submerged Aquatic Vegetation in Virginia and the Chesapeake Bay. See text for explanation.Restoring the Bay's eastern habitat is an important component of Virginia's cleanup effort. Oysters are nature's critical water cleaner-filters, while underwater grasses (aka "submerged aquatic vegetation," or SAV) absorb nutrients, reduce soil erosion, and provide needed dissolved oxygen, as well as food and habitat, for fish and wildlife. Both oysters and water vegetation have been greatly stressed by nutrient and sediment pollution at levels that continue to threaten their health. Chesapeake Bay oysters have been further decimated by decades of overharvesting, shrinking habitat, and disease. These losses all combine to create a feedback loop which results in even lower water quality, fewer oysters, and less SAV.

Restoration treatments, re-seeding, protective measures, aquaculture promotion, and other bay restoration improvements have played a critical role in preventing further deterioration in both the oyster population and SAV acreage. Although still far below historical levels, the most recent oyster survey for Virginia found that from 2007 to 2015, the number of market oysters increased 350 percent. The Bay-wide goal for 2025 is to restore native oyster habitat and populations in 10 tributaries. As of 2014, three tributaries in Virginia -- the Lynnhavem, Lafayette, and Piankatank rivers -- are under restoration.

Underwater grasses in the entire Chesapeake Bay reached an estimated 30-year high of 91,621 acres in 2015, nearly half of its 2025 goal of 185,000 acres (also its historical high). For Virginia segments of the Chesapeake Bay and its tidal tributaries, SAV acreage estimates have increased each year since 2012, from 12,468 acres to 19,071 in 2015. However, this amount is still lower than the previous high of 19,675 acres in 2010.

Blue Crab Populations in the Chesapeake Bay. See text for explanation.The Chesapeake Bay blue crab has been among the biggest beneficiaries of water quality improvements. The Bay's adult population of blue crabs increased substantially after 2008, when emergency management measures were put into place to address severe population declines. However, after reaching a record 20-year high of 764 million in 2012, the blue crab population plunged in 2013 to 297 million. It has since rebounded to 553 million in 2016. The number of adult female crabs — a key indicator of the population's health — has also improved, from a decade-low of 68.5 million in 2014 to 194 million in 2016. Although encouraging, this number remains below both the target level of 215 million and the previous recent high of 246 million attained in 2010.

Impaired Waterways in Virginia. See text for explanation.

Impaired Waters

Under the Clean Water Act, a body of water not meeting established quality standards is classified as "impaired." In 2014, approximately 16,039 miles of Virginia's streams and rivers were impaired; the total impaired area for large, public-use lakes was 94,766.

The number of Virginia's impaired waterways that have been restored is slowly increasing. In 2014, 70.2 percent of rivers and streams, 83.0 percent of lakes, and 87.3 percent of bays and estuaries were assessed as impaired. Although the percentage of impaired rivers and streams increased (from 68.3% in 2010), both lakes and bay waters saw reductions from their 2010 percentages of 85.8 and 93.8, respectively.

Impairments Found in Virginia Rivers. See text for explanation.Impaired waters fail to meet the designated standards for all the uses they were assessed for, including recreation (swimming and boating), fish consumption, and aquatic life. Being deemed impaired does not mean that the water is necessarily harmful for every purpose or that the impairment is always attributable to human pollution. Many waters are designated impaired because bacterial limits are exceeded, which makes them unsuitable for human recreation and for use as a public water source -- yet aquatic life abounds and fish consumption is also possible.

Impairments Found in Virginia Lakes and Reservoirs. See text for explanation.In 2014, for example, 71.9% of Virginia streams were assessed as impaired for recreation, 53.3% for fish consumption, and 34.9 percent for aquatic life -- meaning that two-thirds of Virginia rivers and streams overall met water quality standards for fish and other aquatic species.

Conversely, excess nutrient levels leading to problems like algae bloom tend to be much higher in more fragile and/or slower-moving bodies of water, such as lakes and reservoirs. As a result, many Virginia lakes and reservoirs are fine for recreational use and as public water supplies (since the water will be cleaned), but they tend to have higher rates of impaired fish and aquatic life.

Impairments Found in Virginia Bays and Estuaries. See text for explanation.It is clear from the graph at right that Virginia's bays and estuaries suffer the most heavily from impairment of fish consumption (99.3% in 2014) and aquatic life (94.8%). The good news is that, thanks to efforts such as the Clean Water Act and other legislation banning their use, very few Virginia waterways of any kind are judged impaired because of the presence of highly toxic chemicals, such as polychlorinated biphenyls (PCBs).


Wetlands play a vital role in maintaining water quality: They filter nutrients and sediment from water runoff, help control erosion and flooding, and are an important element in recharging underwater aquifers, which are so critical to water supply. Wetlands also support aquatic life and wildlife habitat. The Commonwealth is committed to improving the condition, number, and area of wetlands throughout the state via public education, regulation and permitting, and mitigation banks.

According to the USDA's Natural Resources Conservation Service, Virginia had approximately 1.55 million total acres of freshwater and saltwater marsh in 2012; this is little changed since 1992 (1.57 million acres) and within the range of statistical measurement error. However, that doesn't mean there has been no loss of wetlands or that they are free from the affects of development.

Virginia Wetlands, in Millions of Acres
  1992 1997 2002 2007 2012
Freshwater Marsh 1.383 1.368 1.364 1.364 1.364
Saltwater Marsh 0.188 0.190 0.190 0.188 0.186
Total Marsh Acreage 1.571 1.558 1.554 1.552 1.550
Source: USDA Natural Resources Conservation Service, 2012 National Resources Inventory

Standards set in 2008 by the Army Corps of Engineers and the EPA require that states work to avoid compromising wetlands, to minimize any impacts -- and to compensate for any losses that are unavoidable. In Virginia the latter is accomplished through a compensatory mitigation policy, managed by the Virginia Department of Environmental Quality (DEQ), that includes the following strategies:

  • Purchase or use of wetland mitigation bank credits at a DEQ-approved mitigation bank
  • Contribution to a DEQ-approved in-lieu fee fund
  • Wetland creation or restoration
  • Stream restoration

From FY 2001 to FY 2015, Virginia saw 2,523 acres of wetlands compromised by development. This loss was offset through restoration of more than 10,000 acres of wetlands across the state.

Virginia also helps accomplish the goals for 2025 outlined in the recent multi-state Chesapeake Bay agreement, which include increasing the Bay's overall wetland capacity by creating 85,000 new acres of wetlands and rehabilitating an additional 150,000 acres of degraded wetlands.

Water Supply

The Earth's groundwater and surface waters are finite resources. In fact, freshwater comprises just 2.5 percent of the planet's entire water supply (96.5% is saline ocean water) -- and humans everywhere, including Virginians, face serious future water quality and availability challenges, thanks to aquifer depletion, climate change, and excessive public and industry water usage.

Depletion of the Coastal Plain Aquifer System is the Commonwealth's most acute water supply issue. This key groundwater resource is affected by the settling of ancient meteorite crater sediments that has led to sea-level rise and greater saltwater intrusion. The Virginia Coastal Plain Groundwater Initiative was created to identify ways to address the loss of this vital resource, including reducing groundwater withdrawals to bring the aquifer into better balance with natural recharge.

Water withdrawal elsewhere in the state has the potential to reduce stream flows, as well as lake and reservoir water levels that are needed to support fish, wildlife and recreation activities.

Virginia water usage has stabilized in recent years, but is projected to rise again in the future. The Virginia Water Use Data System (VWUDS) characterizes water withdrawals by type (see table below).

Water Withdrawals in Virginia, by Use Category and Source Type
(in Millions of Gallons Daily)
Water Use 2010 2011 2012 2013 2014
Agriculture 24 30 31 33 33
Commercial 14 13 12 12 15
Irrigation 35 29 30 19 30
Manufacturing 432 382 386 379 372
Mining 22 19 14 16 14
Other 3 3 3 3 3
Public Water Supply 785 775 752 740 752
TOTALS 1315 1251 1228 1202 1219
Source: Virginia Dept. of Environmental Quality, Water Use Data System

Overall water usage has decreased by two percent across 2010-2014. Most major users also decreased their water withdrawals, including a drop of one percent in public water consumption and five percent in manufacturing consumption. These savings have been driven by water conservation efforts, new cooling-system technologies and water recycling practices, and reductions in state manufacturing and mining capacity.

However, the State Water Resources Plan projects that mean daily water demand will increase by approximately 32% (an estimated 450 million gallons of water per day) by 2040, which will certainly necessitate increased surface and groundwater withdrawals.

Marine Debris

Map showing Pacific Ocean currents and the gyres that are creating large garbage patches there. See text for explanation.Humans produce about 200 billion pounds of plastic waste every year (e.g., straws, plastic bags, food and beverage containers, water bottles, balloons). About 10% of this trash -- or 20 billion pounds annually -- ends up in the ocean, where it breaks down extremely slowly; entangles, chokes, and poisons wildlife; and releases chemical toxins into the water. These plastics accumulate and often wind up swirling around one of five oceanic gyres -- regions where currents push water in an inward circular motion, trapping it in the center -- and create enormous floating "garbage patches." Some of this debris is plainly visible, but older garbage breaks down into small pieces of floating plastic that are not immediately evident to the naked eye. Several garbage patches are located in the Pacific Ocean; another large patch was recently found in the North Atlantic Ocean.

Virginia's own coastal areas are also increasingly affected by marine debris that originates in the state, as well as from around the globe. Although there are no firm estimates of the scale and growth of this type of pollution, evidence suggests that it is more prevalent off the Virginia coast than elsewhere in the eastern US and that the quantity of marine debris in area waters is increasing.

What Influences Water Quality?

Point vs. Non-point Sources

Water quality is degraded when toxic chemicals, biological waste, sediment, and excess nutrients (particularly nitrogen and phosphorous) flow into rivers, streams, wetlands, and coastal waters. Pollutants are categorized as coming from one of two sources: point sources, where the cause has a single known point of origin into state waters (such as a factory discharge pipe); and non-point sources, where pollutants come from diffuse origins, as with storm water runoff or groundwater. Runoff works gradually into streams, lakes, rivers, and eventually bays and other saline bodies from farms, septic fields, paved surfaces, and lawns. Water can also be polluted from the air -- for example, from acid rain. Understandably, it is easier to control pollution from point sources than from non-point ones.

Point source discharges and some non-point sources (for example, farms and golf courses) are regulated under federal and state law. However, a significant number of non-point sources still fall under voluntary, incentive-based programs. Together, these non-point sources -- both permitted and not -- account for most of an increasing share of Virginia's water pollutant and stormwater runoff problems. For example, less than 20 percent of the nutrient pollutants found in the Chesapeake Bay in 2016 can be attributed to point sources in Virginia; the remaining 80 percent come from farms, residential lawns, paved surfaces, and other non-specific sources across the state.

Curbing Pollution

Water pollution can be limited in one of two ways: Either stop the pollution from occurring to begin with, or clean up the contaminated water before it enters public flows. For instance, homeowners and farmers can be encouraged to refrain from using certain fertilizers, herbicides, and pesticides; however, without widespread education on the issue and/or standardized regulation and enforcement, these common practices are proving challenging to change.

The federal Environmental Protection Agency (EPA) makes states responsible for Clean Water Act regulations, so Virginia enforces these as well as state-generated water laws.

Informative state rankings on all aspects of water quality do not exist at this time. Cross-state comparisons must take into account the size of the economy, population, state hydrology, and pollutants coming in from other states or regions. However, states within the Chesapeake Bay watershed report annually on nitrogen, phosphorus, and sediment discharges into the Chesapeake Bay and its tributary rivers. Due to long-term joint agreements among these states to limit pollution, excess nutrient discharges into the Chesapeake Bay in recent years have been generally decreasing. (See table above.)

It is important to note that some water pollutants are not under Virginia's direct control. For example, the level of mercury in state waters is largely determined by mercury emissions that enter the atmosphere outside of the state, and even outside of the country.

What is the State's Role?

Virginia implements a variety of programs to reduce the pollutants that harm water quality through the Department of Environmental Quality, the Department of Conservation and Recreation, the Department of Forestry, and the Department of Agriculture and Consumer Services.

The Water Quality Improvement Fund (WQIF) provides state matching funds for point and non-point source projects that reduce nutrients and other pollutants flowing into Virginia's waters, including the Chesapeake Bay. The Virginia Water Resources Plan assesses the long-term sustainability of the state's water resources; describes threats to water quality; and identifies investments to promote conservation, improve water infrastructure, and expand public education.

The state's choices about how to reduce pollution and conserve water resources certainly affect how much it costs to achieve a given water quality standard or goal -- considerations that must try to balance water quality goals with the cost of doing business. However, there is no doubt that clean and vibrant waters will in the long term sustain and improve Virginia's economic condition and quality of life.

What Can Citizens Do?

Individuals and groups are strongly encouraged to be active participants in resource management, including recycling and mindful disposal of garbage (including a host of toxic products). Judicious use of fertilizers, herbicides, and pesticides is also recommended. Citizens can improve water use efficiency and conservation by fixing leaking pipes; installing rain barrels and low-flow toilets, shower heads and faucet aerators; washing only full loads in laundry washers and dishwashers; and reducing excessive lawn irrigation.

To learn more about Virginia's environment, stewardship and public participation opportunities, or partners engaged in conservation, you may also explore Virginia Naturally, DCR's gateway to statewide environmental education, volunteer opportunities, school programs, etc.

Page last modified September 26, 2016
SAV acreage in Virginia waters.
Blue Crab Population in the Chesapeake Bay.
Impaired Watersways in Virginia.
Impaired Rivers and Streams in Virginia.
Impaired Lakes and Reservoirs in Virginia.
Impaired Bays and Estuaries in Virginia.
Map of Known Garbage Patches in the Pacific Ocean.

State rankings are ordered so that #1 is understood to be the best.

Data Definitions and Sources

Chesapeake Bay Data

Environmental Protection Agency

Assessment and Total Maximum Daily Load Tracking and Implementation System (ATTAINS)

NOTE: There are six designated uses for Virginia water bodies that are tested for water quality: (1) aquatic life—supports the protection and growth of aquatic life; (2) fish consumption—supports human consumption of recreational and commercial fish; (3) shellfishing – supports the human consumption of recreational and commercial fish; (4) recreation – supports swimming, boating, and other recreational activities; (5) public water supply – supports human consumption of drinking water; and (6) wildlife – supports the protection and growth of non-aquatic wildlife.

Virginia Department of Environmental Quality

Wetlands Data

USDA, Natural Resources Conservation Service, National Resources Inventory, 2012 Summary Report
Table 19 - Wetlands and deepwater habitats on water areas and non-Federal land, by state and year.

Virginia Department of Environmental Quality,

General Information

See the Data Sources and Updates Calendar for a detailed list of the data resources used for indicator measures on Virginia Performs.

At a Glance:
Water Quality in Virginia

Performance Trend:  Trend is improving!
State Influence:  

Virginia by Region: The Chesapeake Bay continues to challenge the states who share responsibility for keeping this critical watershed clean and viable. However, renewed efforts to reduce pollution, nutrient overload, and sediment deposits are making gradual but real progress toward short- and long-term goals. Other state waters -- rivers and streams, lakes and reservoirs -- experience very similar challenges.

Related Agency Measures
State Programs & Initiatives

A new set of strategies for further combatting Chesapeake Bay pollution was enacted by the EPA in late 2010 to put impaired waterways on a "pollution diet." Virginia's Watershed Implementation Plans are in three phases and feature Total Maximum Daily Load (TMDL) targets for each of the 35 segments in Virginia's portion of the watershed that impact the bay.

Stormwater runoff is a major factor in water pollution, especially in urbanized areas, and Virginia localities by law now make formal efforts to manage it.

Through a series of regulations and permits, the Virginia Department of Environmental Quality (DEQ) manages the amounts of nitrogen and phosphorus that are discharged by wastewater treatment plants, industries and other point sources throughout the Virginia portion of the Chesapeake Bay watershed. 

DEQ advises others on the cleanup of soil and groundwater at certain contaminated sites. It also has a cleanup program for storage tank leaks above and below ground, primarily from gasoline stations. Some of these contaminated sites are potentially reusable and are referred to as “brownfields.”

Additional Information
N-print logo. See text for explanation.

Developed by environmental scientists from around the world (including our own University of Virginia), the N-Print Project aims to educate the general public about the causes and effects of nitrogen pollution -- and about how everyday choices made by citizens can help alleviate this growing problem.

Their N-Calculator is one tool that allows individuals to calculate their nitrogen footprint.

The Chesapeake Bay Foundation offers a similar, shorter calculator.