The first Earth Day was in April 1970, right as the U.S.Environmental Protection Agency was established by the Nixon Administration.
In honor of the day, many local events are scheduled to be held today to draw attention to the environment, and how people can help.
But Long Island's environmental challenges are myriad, and progress on solving them is complicated and expensive. Here's a look at 10 of them.
Clean drinking water. The water that flows from Long Island's taps comes from underground aquifers, making Long Island particularly vulnerable to pollution that seeps down through the soil. Contaminant plumes from leaking fuel tanks and old landfills criss-cross local groundwater, along with toxic chemicals spilled years before at dry cleaning shops and Cold War-era factories.
Solution: Increased state and federal dollars for environmental cleanups could speed up remediation, preventing pollution from traveling further. Other options included stepping up enforcement, or increasing financial penalties. The state's brownfields program, which provides tax breaks for developers who build on contaminated land, could require participants to clean up pollution to a greater degree.
Cost. The price for cleaning up groundwater at some of Long Island's most polluted sites ranges from $24 million at the former Lawrence Aviation site in Port Jefferson Station to $45 million to $400 million for 15 former gas-production plants across Long Island.
Energy. Nearly all of Long Island's electricity comes from plants that burn fossil fuels, which are non-renewable and leave the region at the mercy of future oil and natural gas prices. Solar energy has made some inroads, but not enough to make a dent in peak energy demands. A 2005 Long Island Power Authority proposal for a 40-turbine wind farm off Jones Beach died amid concerns about cost, aesthetics and the potential impact on marine and bird life.
Solutions: LIPA and National Grid are weighing the costs to modernize the region's three biggest fossil-fuel-burning plants - at Northport, Port Jefferson and Island Park. The overhaul would make them cleaner and more efficient, fueled mostly by natural gas. LIPA and Con Edison are exploring a plan to erect several hundred wind turbines 13 miles off the Rockaways. LIPA has also approved a 50-megawatt commercial solar project; new federal subsidies have escalated interest in LIPA-funded home solar installations.
Cost. Repowering the E.F. Barrett power plant in Island Park would cost $940 million, while modernizing the Northport and Port Jefferson facilities could add up to a combined $2.2 billion to $2.5 billion, according to LIPA estimates.
Fisheries decline. From the 1970s crash of the Great South Bay's hard clam population to the more recent downturn of winter flounder, marine life that sustained generations of Long Islanders appears to be in trouble. Overfishing has winnowed some species; others have been weakened by pollution, habitat decline or toxic algae such as the brown tide blooms that wiped out much of the bay scallop population.
Solutions: While fishermen and regulators often clash on the best way to manage oceans, some species that were once in decline - such as striped bass - have rebounded after efforts were made to revive them. Federal fisheries managers are looking at new ways to control the number of fish that are caught; one approach would give fishermen the right to harvest a set percentage of the annual harvest of a species, a tactic meant to encourage sustainable fishing practices.
Cost. Although individual harvest shares can cost thousands to the fishermen who hold them,, no one has put an overall price on restoring the nation's fisheries.
Air pollution. Despite improvements in recent years, the air Long Islanders breathe has high levels of smog and soot compared with most other counties in New York state. Part of the problem is pollution that travels east from coal-fired power plants in the Midwest. Locally, car and truck traffic was responsible for more than 60 percent of local ozone-causing emissions, according to state data from 2002. Power plants and other stationary sources comprised about 2.5 percent.
Solutions: Driving less - and using vehicles or fuel types that produce fewer emissions - would reduce local air pollution. Some advocate shifting more of Long Island's road traffic to bus and rail lines through expanded public transit systems and greater use of intermodal transfer stations. So-called "smart growth" tactics advise clustering new development around transit lines and downtown commercial districts.
Cost. No one knows the cost of all the solutions, but Long Island Railroad officials estimate it would cost $1.3 billion to lay a third track between Floral Park and Hicksville.
Sewage. Two-thirds of Suffolk County still relies on septic tanks or cesspools that discharge waste to the soil, an approach better suited for rural areas than a growing county that is home to 1.4 million people. Sewers allow for more dense development, limiting sprawl. Aging sewage treatment plants in Nassau and Suffolk also need upgrades to reduce water pollution in Long Island Sound.
Solutions: While the federal money that helped build Long Island's decades-old sewage treatment plants has largely dried up, budget priorities may change under the Obama adminstration.
Cost.Repairing and updating New York state's wastewater infrastructure will cost an estimated $36.2 billion over the next 20 years, according to the state.
Polluted bays and rivers. Rain sweeps pollutants - pet waste, motor oil, fertilizer runoff and litter - from streets into storm sewers and dumps them in local watersheds, triggering beach closures and making shellfish from the most degraded estuaries unsafe to eat. Plumes from chemical and fuel spills can foul Long Island rivers, which are fed by groundwater.
Solutions:Some municipalities have upgraded storm sewers with absorbent filters that soak up pollution. Replacing hard surfaces with permeable pavement or planted areas would reduce runoff by allowing the ground to filter water. Advocates say state environmental officials should impose stricter limits on water pollution permits.
Cost. Filtration units like those the Village of Babylon is placing in 90 storm drains cost between $5,000 to $6,000 apiece to install. The $125 sponges must be replaced about every year.
Wetlands loss: The marshes along Long Island shores filter polltuion and serve as nurseries for marine life and buffers against storms and flooding. But they are also shrinking - despite laws that since the 1970s have largely protected remaining wetlands from development. State officials estimate that vulnerable marshes on Long Island have lost 25 percent of their acreage since 1974. Potential causes: pollution; changes in tidal flow; rising sea levels; or disruption of the flow of sediment to marshes.
Solutions: Researchers are studying the problem and monitoring vulnerable marshes for clues to their decline. Treatments will likely be site-specific, such as such as spraying sediment layers over marshes where dredging or other forces have deprived wetlands of the material.
Cost. No cost estimates have yet been developed to reverse the situation.
The question of what to do with waste has bedeviled the region since the 1980s, when water quality concerns led lawmakers to pass laws that would eventually close most local dumps. Long Island produces an estimated 3.5 million tons of garbage each year. Of that, about 43 percent gets incinerated, 27 percent is recycled, and 30 percent is hauled off-Island to landfills.
Solutions: Some are pressing to expand capacity of local waste-to-energy incinerator facilities such as the Covanta incinerator in Hempstead, saying garbage can function as a renewable fuel to produce electricity. Others say shipping garbage out by rail would reduce traffic on local roads. Environmental advocates say the region needs to increase recycling and implement other programs that would reduce the overall volume of waste, such as separating compost from other household trash.
Cost. With the issue not addressed regionally, the costs vary by miunicipality and the disposal options each chooses.
Open space preservation. Advocates say preserving open space combats sprawl and is essential to protect the farms, beaches and woods that draw tourists to Long Island. But the less land that remains, the more it costs - a concern when local and state governments are slashing costs and scrambling to balance their budgets.
Solutions.Local governments can buy up development rights as well as purchasing parcels outright. Critics point out that buying up farms and other parcels of land may protect watersheds, but it also spends money that could be used for other environmental purposes - and subtracts millions from property tax rolls.
Cost. Environmental advocate Richard Amper says Suffolk County spent about $1.2 billion on open space purchases in the past three decades. But a Dowling College study funded by the real estate industry put the price tag at $3.5 billion, including authorized future purchases and lost tax revenues.
Climate change. While some remain skeptical, federal and state environmental officials now agree with a large body of international researchers who say that a global increase in temperature is now underway, largely as a result of human activities such as burning fossil fuels. Among the biggest concerns for coastal Long Island: increased flooding as a result of rising oceans, which expand as waters warm and are expected to rise more quickly as a result of melting polar ice.
Solutions. To limit carbon dioxide emissions, federal lawmakers are considering legislation to cap industrial emissions and allow companies to trade pollution allowances. New York state has already signed on to a regional trading scheme to reduce greenhouse gas emissions from power plants. Environmental advocates and some scientists are urging planners to factor climate change and sea level rise into shoreline protection projects and zoning codes.
Cost. An EPA analysis of a draft House cap-and-trade bill said it would have "a relatively modest impact on U.S. consumers," but House Republicans, who oppose the measure, said it would cost families up to $3,100 per year in higher energy prices.