presented by Michael Wireman
This brown bag Webinar is brought to you by the NGWA Economics of Groundwater Interest Group.
Attend this half-hour brown bag Webinar to learn more about how, during the past six to seven decades, nitrate contamination of groundwater has increased dramatically and is a widespread problem in numerous agricultural regions of the United States.
The most common sources of nitrate in groundwater are inorganic fertilizer, animal feeding operations (AFOs), septic tanks, and residual nitrogen in soil. Total nitrogen application to the land surface in the United States increased from less than 550 tons per year in 1945 to approximately 12,000 tons per year in 2001. There are more than 260,000 AFOs within the United States, of which more than 20,000 are concentrated AFOs, or CAFOs. Fertilizer use in the United States increased from 40 pounds per acre in 1965 to about 140 pounds per acre in 2005; its use is not regulated at the state or federal level.
The primary human health problem associated with nitrate is methemoglobinemia (blue-baby syndrome). Possible links to bladder and ovarian cancer from long-term exposure to nitrate concentrations of 2 to 4 mg/L have also been suggested. Nitrate in groundwater also contributes to high nitrate and nitrogen concentrations in streams and lakes. Along gaining reaches of streams in agricultural areas, groundwater discharge (including return flows) can deliver significant loads of nitrogen directly to the stream or, more commonly, to the streambed.
Based on recent data from around the United States, it’s clear that regulatory, voluntary, and programmatic efforts to reduce nitrate contamination of groundwater have not been as successful as intended. A suite of best management practices (BMPs) have been developed to prevent or minimize leaching of fertilizers to the underlying water table and to streams; however, the effectiveness of these BMPs, with respect to the design and application/maintenance is not clear.
Participants may earn 0.05 CEUs by attending this brown bag Webinar.
You may also wish to check with your respective regulatory agency regarding recognition of this brown bag Webinar for continuing education credit.
Though free to NGWA members, connections are limited and preregistration is required.
Registration closes at 5 p.m. ET on July 16, 2012.
Once your registration is processed, you will receive an e-mail confirming your registration. (Please allow at least one full business day for the processing of your registration.) You’ll receive an e-mail invitation with log-in details five days prior to the presentation date. Click on the “registration” button and complete GoToWebinar®’s brief registration process. You will receive an e-mail confirming your registration for the Webinar, along with the option to add the Webinar information to your Outlook® calendar. Please note: Some Webinars may require organizer approval prior to the delivery of a confirmation e-mail. Once you are online for the Webinar, you will be able to type in your questions, as well as print out related materials. (Please view the NGWA Webinar FAQs page for more information including that for GoToWebinar.)
Information current as of 6-25-2012. For further assistance, e-mail email@example.com or call 800 551.7379 (614 898.7791).
800 551.7379 (614 898.7791 outside the United States)
8 a.m.-5 p.m. ET Monday through Friday
fax 614 898.7786
PO Box 715435
Columbus, OH 43271-5435
National Ground Water Association
601 Dempsey Rd.
Westerville, OH 43081
(614 898.7791 outside the US)
fax 614 898.7786