Navigation Links
Chloride found at levels that can harm aquatic life in urban streams of the Northern US
Date:9/16/2009

Levels of chloride, a component of salt, are elevated in many urban streams and groundwater across the northern U.S., according to a new government study.

Chloride levels above the recommended federal criteria set to protect aquatic life were found in more than 40 percent of urban streams tested. The study was released today by the U.S. Geological Survey (USGS). Elevated chloride can inhibit plant growth, impair reproduction, and reduce the diversity of organisms in streams.

The effect of chloride on drinking-water wells was lower. Scientists found chloride levels greater than federal standards set for human consumption in fewer than 2 percent of drinking-water wells sampled in the USGS study.

Use of salt for deicing roads and parking lots in the winter is a major source of chloride. Other sources include wastewater treatment, septic systems, and farming operations.

"Safe transportation is a top priority of state and local officials when they use road salt. And clearly salt is an effective deicer that prevents accidents, saves lives, and reduces property losses," said Matthew C. Larsen, USGS Associate Director for Water. "These findings are not surprising, but rather remind us of the unintended consequences that salt use for deicing may have on our waters. Transportation officials continue to implement innovative alternatives that reduce salt use without compromising safety."

This comprehensive study examines chloride concentrations in the northern U.S. covering parts of 19 States, including 1,329 wells and 100 streams.

Selected Highlights

Land use matters

Chloride yields (the amount of chloride delivered per square mile of drainage area) were substantially higher in cities than in farmlands and forests. Urban streams carried 88 tons of chloride per square mile of drainage area. Forest streams carried about 6 tons of chloride per square mile.

Only 4 percent of the streams in agricultural areas had chloride levels that exceeded the recommended federal criteria set to protect aquatic life (compared to more than 40 percent of urban streams). Overall, 15 percent of all streams had chloride levels exceeding the criteria.

Chloride concentrations in shallow groundwater (not used for drinking) were 16 times greater in urban areas than in forests, and 4 times greater in urban areas than in agricultural areas.

Highest levels in streams in the winter

In urban streams, the highest levels of chloride (as great as 4,000 parts per million, which is about 20 times higher than the recommended federal criteria) were measured during winter months when salt and other chemicals are used for deicing.

Increases over time

Increases in chloride levels in streams during the last two decades are consistent with overall increases in salt use in the U.S. for deicing.

Increasing chloride yields are linked to the expansion of road networks and parking lots that require deicing, increases in the number of septic systems, increases in wastewater discharge, and increases in saline groundwater from landfills.

Sources can vary locally

Chloride in ground and surface waters comes from many sources including the use and storage of salt for deicing roads, septic systems, wastewater treatment facilities, water softening, animal waste, fertilizers, discharge from landfills, natural sources of salt and brine in geologic deposits, and from natural and human sources in precipitation.


'/>"/>

Contact: John Mullaney
jmullane@usgs.gov
860-291-6760
United States Geological Survey
Source:Eurekalert

Related biology news :

1. Exotic timber plantations found to use more than twice the water of native forests
2. Anticancer compound found in American mayapple
3. Shifting baselines confound river restoration
4. NTU and Temasek Foundation transfer technology knowhow to Chinas quake-prone regions
5. Newly found DNA catalysts cleave DNA with water molecule
6. Essential nutrient found in eggs may help lower risk of neural tube defects
7. Little-known protein found to be key player
8. 121 breeding tigers estimated to be found in Nepal
9. Possible drug target found for one of the most aggressive breast cancers
10. Will IVF work for a particular patient? The answer may be found in her blood
11. UTSA wins San Antonio Area Foundation grant to further chlamydia research
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/15/2016)... JERUSALEM , March 15, 2016 ... Jerusalem , the technology-transfer company of the Hebrew University, ... developer of remote sensing technology of various human biological ... funding, raising $2.0 million from private investors. ... technology, based on the detection of electromagnetic emissions from ...
(Date:3/14/2016)... Allemagne, March 14, 2016 ... - --> - Renvoi : image disponible ... --> --> DERMALOG, ... fournit de nouveaux lecteurs d,empreintes digitales pour l,enregistrement ... DERMALOG sera utilisé pour produire des cartes d,identité ...
(Date:3/11/2016)... PUNE, India , March 11, 2016 ... to a new market research report "Image Recognition Market ... by Application (Marketing and Advertising), by Deployment Type (On-Premises ... Global Forecast To 2022", published by MarketsandMarkets, the global ... in 2015 to USD 29.98 Billion by 2020, at ...
Breaking Biology News(10 mins):
(Date:5/3/2016)... May 3, 2016  Dr. Thomas P. McHugh ... The Woodlands, Texas , now offers ... of treated fat cells in just 25-minutes, leaving a ... 90 percent of Americans report feeling bothered by excess ... reduction procedures are a growing industry. This innovative new ...
(Date:5/2/2016)... YORK , May 2, 2016 ... announces that its technology partner Mannin Research Inc. will ... Ophthalmology (ARVO), which takes place from May 1-5, 2016 ... executives will be meeting with its vendors and research ... explore business development goals and other collaborative opportunities for ...
(Date:5/2/2016)... , ... May 02, 2016 , ... ... report on the pre-launch success of their revolutionary, veterinarian-designed product for indoor cats. ... stalk, trap, and play with their food the way nature intended. NoBowls make ...
(Date:4/29/2016)... ... April 29, 2016 , ... Amendia, Inc., a ... procedures, today announced the completion of a significant transaction and partnership that positions ... customers and partners. Kohlberg & Company, L.L.C. (“Kohlberg”), a leading private equity ...
Breaking Biology Technology: