Recently in Urban waterways Category
Ecosystems suffer first. Terminus lakes could benefit from a new desalination system being developed at the University of Nevada, Reno.
Terminus lakes are located in closed-basin regions where there is no outflow for the water and a high evaporation rate, leaving a high concentration of minerals and salts.
This new, low cost way to desalinate water uses a specialized low-cost solar pond and patented membrane distillation system powered by renewable energy.
Hundreds of terminus lakes worldwide such as the Great Salt Lake, the Salton Sea in California, the Aral Sea and Nevada's Walker Lake are experiencing a decline in water levels and an increase in salinity from both human and natural processes," says Francisco Suarez, a doctoral student in hydrological sciences.
Suarez is developing an artificial salt-gradient stratification process that traps solar heat at the bottom of the solar pond and uses the collected energy to power the membrane distillation system recently patented by the University. The hot brine in the lower storage zone of the pond, which can reach temperatures greater than 195 degrees Fahrenheit, may be used directly for heating, thermal desalination, or for other low-temperature thermal applications.
The process has been highly successful in the lab in a small-scale experiment using a 400-gallon tank, where dissolved solids and precise fiber-optic temperature sensing are being used to track the process as it desalinates the water. The next step for Suarez and the research group is to build a pilot-project, demonstration-scale, low-temperature desalination system in an open environment.
This desalination system is designed to help sustain the ecosystems of these closed-basin regions.
Read more about this desalination system at the University of Nevada
What is "car habitat"?
"...the geometry of roads, parking lots, sidewalks, cul-de-sacs and other new development infrastructure." That's car habitat.
Local development codes enforce how much impervious surface is allowed. They take into consideration how water drains and is absorbed by local soil conditions, as well as the level of development already affecting the watershed.
Better site design can reduce flooding by improving absorption of heavy water deluges into nature's groundwater infrastructure. Snowpack might be nature's LARGEST water reservoir, but groundwater is also a very valuable service provided by nature in lowlands.
Better Site Design (BSD), can include greater use of
- swales
- relaxed lot geometry
- natural area conservation
- open-space subdivisions
- pervious paving
- and other site design techniques
Several dozen communities across the country have changed their local codes and ordinances to promote BSD through a roundtable process to gain consensus among development stakeholders.
Better Site Design Can Reduce Development Costs
The strength of the BSD approach is that numerous modeling studies have demonstrated it can reduce impervious cover, pollutants and development costs by as much as 10 to 40% at individual development sites.
The weakness of BSD is that it lacks a watershed context and therefore reductions in site IC may be not be enough to meet subwatershed objectives.
SOURCE:
Chesapeake Stormwater Network, CSN Technical Bulletin No. 3, "Implications of the Impervious Cover Model".
PCB Contamination in Aquatic Habitat
Scientists examined PCB (polychlorinated biphenyls) levels in shoreline-living spiders at Lake Hartwell, a Superfund site in South Carolina, and used this information to map contaminant concentrations in lake sediment.
Future monitoring studies will use the spiders as indicators of ecosystem recovery from PCB contamination.
Researchers also made risk maps for a spider-eating bird, the Carolina wren, which could be exposed to PCBs through eating spiders. These spiders rely heavily on adult aquatic insects for food and play a key ecological role in the transfer of contaminants between water and land ecosystems. In spite of this, they are underused as a sentinel species at contaminated sediment sites.
This study, "Using riparian spiders as sentinels of PCB export and risk" was conducted by USGS at the Society of Environmental Toxicology and Chemistry and the EPA.
Contamination of urban lakes and streams by polycyclic aromatic hydrocarbons (PAHs) is widespread and has been increasing over the last 40 years in the United States.PAHs are Toxic to Fish Humans and Other Organisms
These PAHs can be toxic to bottom-dwelling organisms, can cause tumors in fish, and several are believed to cause cancer in humans.
In this study, researchers examined five sources of PAHs in 40 urban lakes from across the United States, including coal-tar-based pavement sealcoat, coal combustion, oil combustion, vehicle emissions and wood combustion.
Sealcoat Contributes to PAH Contamination
Of the five sources studied, sealcoat was the strongest contributor to PAH contamination in lake sediment. This research can help those trying to reduce pollution levels in the urban environment by providing them with a better understanding of PAH sources.
This study, "Sources of PAHs to urban lakes in the United States," was conducted by USGS at the Society of Environmental Toxicology and Chemist
The Imperial Highway Sunken Median Stormwater Best Management Practices (BMP) project
I drive by the Imperial Highway project almost daily, and watched this biofiltration system being constructed. Cool! Here are more details about how it filters urban runoff from residential and industrial areas that has been draining into the Santa Monica Bay and the Pacific Ocean. It is one more way to protect the fragile habitat and wildlife ecosystem under stress in the Bay.
Sunken Median Stormwater Diversion
This urban street median stormwater project is located on Imperial Highway between Pershing Drive and Main Street in El Segundo, CA. It is in a highly traveled street that divides LAX Airport and the residential neighborhoods of El Segundo. It also leads directly to Santa Monica Bay and the Pacific Ocean...just down the street.

Los Angeles and El Segundo reduce pollutants to Santa Monica Bay with Biofiltration System.
Biofiltration System of Vegetated Swales and Trench
The stormwater runoff project installed a biofiltration system comprised of vegetated swales and an infiltration trench that will collect runoff from a 7.5-acre area and remove bacteria, oil, trash and suspended solids from stormwater that would otherwise be discharged to Santa Monica Bay. Shrubs and trees were also planted in the project area, and an automated irrigation system that uses recycled water was installed.Elevated concentrations of pesticides in streams can affect aquatic organisms in streams as well as the quality of drinking water in some high-use areas where surface water is used for municipal supply.Decreasing Usage Decreases Stream Contamination...???!
Concentrations of several major pesticides mostly declined or stayed the same in "Corn Belt" rivers and streams from 1996 to 2006, according to a new U.S. Geological Survey study.
The declines in pesticide concentrations closely followed declines in their annual applications, indicating that reducing pesticide use is an effective and reliable strategy for reducing pesticide contamination in streams.
Declines in concentrations of the agricultural herbicides cyanazine, alachlor and metolachlor show the effectiveness of U.S. Environmental Protection Agency (EPA) regulatory actions as well as the influence of new pesticide products.
In addition, declines from 2000 to 2006 in concentrations of the insecticide diazinon correspond to the EPA's national phase-out of nonagricultural uses. The USGS works closely with the EPA, which uses USGS findings on pesticide trends to track the effectiveness of changes in pesticide regulations and use.
Stream Pollutants in llinois, Indiana, Iowa, Nebraska and Ohio
Scientists studied 11 herbicides and insecticides frequently detected in the Corn Belt region, which generally includes Illinois, Indiana, Iowa, Nebraska and Ohio, as well as parts of adjoining states.
This area has among the highest pesticide use in the nation -- mostly herbicides used for weed control in corn and soybeans. As a result, these pesticides are widespread in the region's streams and rivers, largely resulting from runoff from cropland and urban areas.
Four of the 11 pesticides evaluated for trends were among those most often found in previous USGS studies to occur at levels of potential concern for healthy aquatic life. Atrazine, the most frequently detected, is also regulated in drinking water.
"Pesticide use is constantly changing in response to such factors as regulations, market forces, and advances in science," said Dan Sullivan, lead scientist for the study. "For example, acetochlor was registered by the EPA in 1994 with a goal of reducing use of alachlor and other major corn herbicides -- acetochlor use rapidly increased to a constant level by about 1996, and alachlor use declined. Cyanazine use also decreased rapidly from 1992 to 2000, as it was phased out because of environmental concerns. Metolachlor use did not markedly decrease until about 1998, when S-metolachlor, a more effective version that requires lower application rates, was introduced. Each of these declines in use was accompanied by similar declines in concentrations."
Although trends in concentration and use almost always closely corresponded, concentrations of atrazine and metolachlor each declined in one stream more rapidly than their estimated use. According to Skip Vecchia, senior author of the report on this analysis, "The steeper decline in these instances may be caused by agricultural management practices that have reduced pesticide transport, but data on management practices are not adequate to definitively answer the question. Overall, use is the most dominant factor driving changes in concentrations."
Simazine Shows Increased Usage
Only one pesticide -- simazine, which is used for both agricultural and urban weed control -- increased from 1996 to 2006. Concentrations of simazine in some streams increased more sharply than its trend in agricultural use, suggesting that non-agricultural uses of this herbicide, such as for controlling weeds in residential areas and along roadsides, increased during the study period.
The USGS study is based on analysis of 11 pesticides for 31 stream sites in the Corn Belt for two partially overlapping time periods: 1996 to 2002 and 2000 to 2006. Pesticides included in the trend analyses were the herbicides atrazine, acetochlor, metolachlor, alachlor, cyanazine, EPTC, simazine, metribuzin and prometon, and the insecticides chlorpyrifos and diazinon. Additional detailed analyses of relations between concentrations and use focused on four herbicides mainly used for weed control in corn (atrazine, acetochlor, metolachlor and alachlor) at a subset of 11 sites on the main rivers and selected large tributaries in the Ohio, Upper Mississippi and Missouri River basins.
Concentrations of many other pesticides that were less prevalent than the 11 included in the study were below analytical detection limits in most samples and thus could not be analyzed for trends.
Glyphosate, the most heavily used herbicide in the US
Glyphosate, an herbicide which has had rapidly increasing use on new genetically modified varieties of soybeans and corn, and which now is the most heavily used herbicide in the nation, was not measured until late in the study and thus had insufficient data for analysis of trends.
A USGS Scientific Investigations Report, "Trends in Pesticide Concentrations in Corn-Belt Streams, 1996-2006," (Analysis of concentration trends for 11 pesticides at 31 stream and river sites) and a journal article in the Environmental Science and Technology journal, "Trends in Concentrations and Use of Agricultural Herbicides for Corn Belt Rivers" (Analysis of concentration and use trends for 4 herbicides at 11 major river sites) is available online. Additional information, including data, reports and maps on pesticide status, trends and use may be found at the USGS Pesticide National Synthesis Project Web site.
USGS provides science for a changing world. For more information, visit www.usgs.gov.
The Los Angeles Times reported on the controversial new policy and traced the history of water and sewer wars in this Pacific beach town. In many ways, the septic tanks played a large role in Malibu becoming a city. It incorporated and formed its own government in 1991 to stave off Los Angeles County's efforts to install a sewer system in the area. Residents at the time feared sewers would unleash a wave of development that would turn Malibu into Miami Beach West.
But sewer has also become the undoing of the community. Malibu septic tanks, leach pits and the ubiquitous stench known as the "Malibu smell" are not so elegant, but frequent topics. Officials often post signs on Surfrider Beach after rainstorms urging swimmers and surfers to stay away because of health dangers. Surfrider Beach often gets failing grades on Heal the Bay's annual beach water-quality report cards.
Joe Melchione, chairman of the Malibu Surfing Assn.'s environmental committee, spoke out against the beach contamination at a 10-hour meeting Thursday at the Metropolitan Water District headquarters. Another member of the surfing group exhibited the scar on his chest, where a pacemaker was implanted because of the viral myocarditis he contracted after paddling through raw sewage at Surfrider Beach in the summer of 1997.
The Los Angeles Regional Water Quality Control Board agreed to ban septic systems in central and eastern Malibu, a move that would end years of fierce debate over the wastewater devices still commonly used in one of Southern California's most picturesque and exclusive coastal communities.
New septic systems will not be permitted in Malibu and owners of existing systems will have to halt wastewater discharges within a decade.
The shift to a sewer system comes at considerable expense. Residents in affected areas would be required to pay about $500 a month to cover the cost of hooking into a central sewage system, according to the city's projections. And businesses would face payments of up to $20,000 a month.
This community battle resulted in the city being sued both FOR and FOR NOT providing specific sewer solutions. This battle is indicative of the battles to come as more communities grapple with water quality issues that have to be woven into complex community infrastructure and natural ecosystem challenges.
Many of these trapped juvenile fish, commonly known as smolts, have either been plucked out of isolated pools by birds and other predators or died from lack of nutrients, biologists with the Salmon Protection and Watershed Network said.
The stranding of smolt trying to reach the ocean is one of a litany of problems facing the endangered Central California coho population, which registered the lowest number of egg-laying adults in the normally bountiful Lagunitas watershed in recorded history last winter.
It is unique in that the primary spawning grounds are in the middle of developed communities. Some 40 percent of the coho in the watershed are hatched in tributaries surrounded by homes, golf courses, roads and horse corrals in the 9-square-mile San Geronimo Valley, according to the study.
It is estimated that between 3,000 and 6,000 coho swim down the waterway back to the ocean every year. The plummeting coho numbers exacerbate a near-catastrophic decline in the overall population of salmon along the West Coast. The coho population around the state has declined precipitously over the years and so few chinook salmon returned to spawn in the Sacramento-San Joaquin River system the past two years that ocean fishing had to be banned in California and Oregon.
Read more: http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2009/10/09/BA031A1G5O.DTL&tsp=1#ixzz0TktW6zSA
Federal agencies released the seven draft reports required by President Obama's executive order on the Chesapeake Bay , which contain a range of proposed strategies for accelerating cleanup of the nation's largest estuary and its vast watershed.
Focus is on increased accountability and performance
The draft reports collectively call for increased accountability and performance from pollution control, habitat protection and land conservation programs at all levels of government, including an expanded use of regulatory authorities to address pollution control and additional voluntary and market-based solutions - particularly when it comes to habitat protection and land conservation programs. Federal agencies are also proposing new ways to harness the latest innovations in science and technology. The proposed actions are in response to overwhelming scientific evidence that the health of the Chesapeake Bay remains exceptionally poor, despite the concerted restoration efforts of the past 25 years.
"We need bold new leadership, collective accountability by all contributors to the bay's problems, and dramatic changes in policies using all the tools at hand if we are to fulfill President Obama's goal for clean water throughout the region. These reports bring us a step closer to achieving the vision we all share for the future of the Chesapeake Bay ," said U.S. Environmental Protection Agency Administrator Lisa P. Jackson, chairperson of the Federal Leadership Committee and the federal representative to the Chesapeake Executive Council.
The draft reports are the first step in the creation of a new strategy for restoring and protecting the Chesapeake Bay and waterways in the region, as defined by the executive order.
The reports include a variety of strategies and options for addressing issues such as
- water quality,
- public access,
- landscape conservation,
- climate change,
- scientific monitoring and
- protection of living resources
The draft reports were also submitted to the Federal Leadership Committee that is coordinating work on the executive order. The draft reports are available at http://executiveorder.chesapeakebay.net .
Executive Order 13508 on Chesapeake Bay Restoration and Protection
On May 12, 2009 President Obama issued Executive Order 13508 on Chesapeake Bay Restoration and Protection, the first-ever presidential directive on the bay and the first environmental executive order by President Obama.
Multidisciplinary Federal Leadership Committee
The order established a Federal Leadership Committee, chaired by EPA, and with senior representatives from the departments of Agriculture, Commerce, Defense, Homeland Security, Interior and Transportation.
Over 120 days, 10 federal agencies collaborated to develop the draft reports. The recommendations in the reports were shaped by consultations with the six states in the Chesapeake Bay watershed and the District of Columbia , as well as suggestions from stakeholders and the public. Successful restoration of the Chesapeake Bay depends on the involvement of federal, state and local governments; the private sector; nonprofit organizations; and the watershed's 17 million residents. The draft reports were released to engage the public in the process outlined in the executive order.
The draft report on water quality includes some of the more significant potential changes to existing programs.
In this report, EPA proposes to develop new regulations for the Chesapeake Bay to significantly reduce runoff pollution from urban, suburban and agricultural sources.
The report also relays EPA's intention to hold the states in the watershed more accountable for controlling pollution, through increased oversight, enforcement activities and new policies.
Urban and suburban runoff pollution is the fastest growing source of pollution to the Chesapeake Bay , while agricultural runoff is the largest.
The Federal Leadership Committee will evaluate the proposals in the draft reports and consult with bay jurisdictions to refine the recommendations for meeting key challenges to the Chesapeake Bay 's health. However, the agencies will be moving forward in a number of areas before the strategy becomes final.
"We have an urgent obligation to citizens of today and generations of tomorrow to restore the Chesapeake Bay and its watershed, and this executive order puts new weight behind our work," Jackson said. "We're moving quickly and transparently on a comprehensive strategy that will get real results for the bay."
More information on the executive order: http://executiveorder.chesapeakebay.net
