Understanding and Protecting

Long Island’s Drinking Water - -

The Water Below

Sarah MeylandDirector, Center for Water Resources

Management, NYIT1

Water for Long Island

• Long Island is the largest island in the continental U.S.• 120 miles long and 20 miles wide

• L.I. is underlain by 3 main water-bearing geologic formations called AQUIFERS.

• The AQUIFERS store all the drinking water for L.I.

• While still in the aquifers, the water is called GROUNDWATER.

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Where is the Groundwater Stored?

In the Sand

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The Long Island Aquifer System

Lloyd Aquifer: +70 million years old

Magothy Aquifer: 65 million years old

Glacial Aquifer: 10,000 years old

Groundwater Divide

Glacial Aquifer stores 62% of all recharge.

Magothy Aquifer receives 38% of recharge.

Lloyd Aquifer receives 3% of recharge.

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Glaciers (10,000-15,000 years ago) shaped Long Island’s

topography; rain and melting ice filled the aquifers with fresh

water

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Groundwater Divide

From the 44-inches of annual rainfall, about half seeps into (recharges) the aquifers to become groundwater each year.

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An Aquifer is like a Bank:

Water In and Water Out

Humans over-pump groundwater in some areas = QUANTITY Problems (saltwater intrusion) Nassau County (north & south shore areas) Suffolk County: North & South Forks Water tables drops and streams dry up

Humans pollute the groundwater by activities on the land = QUALITY Problems Volatile Organic Chemicals (VOCs) = Toxic Chemicals Nitrates (sewage and fertilizer) Spills (gasoline, industrial chemicals) Manufacturing/commercial (> 250 Superfund sites)

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Human Impacts on Groundwater

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Groundwater Contamination Plumes

Septic Tank Discharge Chemical Spill

• Long Island uses about 130 – 150 billion gallons per year.

• Summer water use increases 200 – 400% above winter water use.

• Lawn watering returns NO water back to the aquifer.

• The best water is disappearing.

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How do we use our water?

Water Use through the Year

Excessive Summer Water Use Stresses the Groundwater Supply:

Little Recharge

Source:LI 208 Study

National Average: Per Person Water Use = 100 g/p/day Nassau County: Per Person Water Use = 140 g/p/day Suffolk County: Per Person Water Use = 137 g/p/day

Industrial Water Use on L.I. = Unknown Agricultural Water Use on L.I. = Unknown

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Per Person Water Use on L.I. is

Above the National Average

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Saltwater Intrusion in Nassau County

Who is responsible for LI Water? How is water managed around NY State? Water Compacts – Used Throughout New York Long Island needs it own aquifer manager - -

Long Island Aquifer Management Compact

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How Can Long Island Protect and Manage Its Groundwater Supply?

1. Define how much water is available and how much can be reliably withdrawn, to help stop saltwater intrusion.2. Allocate water among all stakeholders and track water use.3. Oversee water withdrawals and administer water well permit program. 4. Develop short-range and long-range water management plans and implement them. 5. Conduct scientific studies to increase our understanding of the aquifer systems in cooperation with the USGS.

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What would an Aquifer Compact Do?

Be our Groundwater Champion!

6. Develop computer models of the aquifers and management tools for better oversight. 7. Protect water-dependent systems: streams, wetlands, pond, lakes, etc. from water withdrawal impacts & pollution.8. Speed up contaminated site cleanup.9. Combat saltwater intrusion. 10. Promote better ways to protect groundwater quality and improve conservation. 11. Work with all interested parties to make groundwater protection the number 1 priority.

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Compact Responsibilities

1. Promote public education and educational materials.2. Report annually to the public about new information and current conditions.3. Monitor High Risk conditions: drought, salt water intrusion, sea level rise, climate change, new pollutants. 4. Represent the water interests of Long Island in regional situations. 5. Work full-time and develop science-based policies.

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Also, a Compact Would

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We only have one source of drinking water.

We ruin or waste it at our own peril.

Not to scale

QUESTIONS?

1-29-2016