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Research about District of Columbia, Maryland

Source-linked reports with geographic coverage including District of Columbia, Maryland.

4 recordsLinked to original sources
USGS2018

Organochlorine chemical residues in Northern Cardinal (Cardinalis cardinalis) eggs from Greater Washington, DC USA

Northern Cardinal eggs from six neighborhoods near Washington DC were analyzed for organochlorine pesticides and PCBs. All compounds were detected more frequently and at higher concentrations in more heavily urbanized neighborhoods. DDT (mostly as p,pʹ -DDE) was detected in all neighborhoods. p,pʹ -DDT was typically 0.5‒16 ng/g (ww) in most suburban neighborhoods but was not detected (< 0.1 ng/g) in more rural areas; however, p,pʹ -DDT was 127‒1130 ng/g in eggs from two suburban Maryland nests and comprised 65.7% of total p,pʹ -DDT isomers in the most contaminated sample, indicating recent exposure to un-weathered DDT. Total chlordane (sum of 5 compounds) was 2‒70 ng/g; concentrations were greatest in older suburban neighborhoods. Total PCB (sum of detected congeners) was < 5‒21 ng/g. Congener patterns were similar in all neighborhoods and resembled those typical of weathered mixtures. Results indicate that wildlife remains exposed to low concentrations of legacy contaminants in suburban neighborhoods and that cardinal eggs can be used to monitor localized contamination.

District of Columbia, Maryland↗
USGS2015

The hydrogeology of urbanization: The lost springs of Washington, D.C., late Tertiary and Quaternary sediments of D.C., and the Baltimore Long Term Ecological Research site (LTER): Chapter

Urbanization is a major process now shaping the environment. This field trip looks at the hydrogeology of the general Washington, D.C., area and focuses on the city's lost springs. Until 150 years ago, springs and shallow dug wells were the main source of drinking water for residents of Washington, D.C. Celebrating the nation's bicentennial, Garnett P. Williams of the U.S. Geological Survey examined changes in water supply and water courses since 1776. He examined old newspaper files to determine the location of the city's springs. This field trip visits sites of some of these springs (few of which are now flowing), discusses the hydrologic impacts of urbanization and the general geological setting, and finishes with the Baltimore Long Term Ecological Research site at Dead Run and its findings. The field trip visits some familiar locations in the Washington, D.C., area, and gives insights into their often hidden hydrologic past and present.

District of Columbia, Maryland↗
USGS1907

Patuxent folio, Maryland-District of Columbia

The Patuxent quadrangle lies between parallel 38&deg; 30' and 39&deg; north latitude and meridians 76&deg; 30' and 77&deg; west longitude. It includes one-fourth of a square dgeree of the earth's surface and contains 931.5 square miles. From north to south it measures 34.5 miles and from east to west the mean distance is 27 miles, the width being 27.1 miles along the southern and 29.6 miles along the northern border.

District of Columbia, Maryland↗