The City of New Orleans is working to recover from Hurricane Katrina's devastating
effects.
As part of recovery efforts, the City has committed to cleaning up soil
contamination to levels that will provide healthy environments for their residents.
This includes remediating areas of lead-contaminated soil.
The Society for Environmental Geochemistry and Health (SEGH) Executive Board has
established a Task Force to provide the
City of New Orleans Office of Recovery Management
with an expert panel report on the relative merits of potential cost-effective
methods for remediation of lead-contaminated soils.
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William Motzer
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After the SEGH New Orleans conference on Urban Geochemistry and Health in July
2007, the New Orleans Office of Recovery Management requested SEGH's help in
understanding the science behind lead-contaminated soil remediation.
As a result, an Issues of Contamination Assessment and Remediation of Urban Soils
(ICARUS) Task Force was formed.
The ICARUS Task Force will use a phased approach by initially compiling and
reviewing available data on the health effects from exposure to lead-contaminated soil
and effective and economic soil remediation, to be followed by data collection and
evaluation of remedial demonstration projects.
Twelve Task Force members have been named, including Dr. William E. Motzer of Todd
Engineers and members of the Tulane/Xavier Center for Bioenvironemtal Research at
Tulane University.
Additional information about SEGH can be obtained at
www.segh.net.
-- April 2008
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Edwin Lin
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Chad Taylor
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We are pleased to announce that Edwin Lin, Senior Geologist with Todd Engineers, and
Chad Taylor, Associate Geologist with Todd Engineers, have recently been awarded their
Professional Geologist licenses by the California Board of Registration for Geologists
and Geophysicists.
Edwin holds a Bachelor of Science degree in Geological and
Environmental Sciences from Stanford University and a Master of Science degree in
Groundwater Hydrology from Flinders University in Australia.
Chad holds a Bachelor of Science degree in Earth Sciences from the
University of California at Santa Cruz.
Congratulations, Edwin and Chad!!
-- March 2008
Sally McCraven, Senior Hydrogeologist with Todd Engineers, has prepared two papers
discussing the fate and transport of N-nitrosodimethylamine (NDMA) in the
environment.
The first presentation, entitled
"Characterizing Field Biodegradation of NDMA in Groundwater Near Reclaimed Water
Recharge Areas",
is scheduled for Wednesday, March
26, 2008 at the
WateReuse Association's 2008 California
Section Annual Conference
in Newport Beach, California.
This presentation is coauthored with
Dr. Quanlin Zhou of Lawrence Berkeley National Laboratory,
Dr. Julio Garcia of Calpine,
Monica Gasca of the County Sanitation Districts of Los Angeles, and
Ted Johnson of the Water Replenishment District of Southern California.
It presents the findings of a multi-year data collection, analysis, and modeling project
conducted in and upgradient of the Montebello Forebay Spreading Grounds
in Southern California.
The project is the first to rigorously demonstrate field evidence of NDMA biodegradation
in groundwater.
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Molecular structure of NDMA
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A second paper -- "Occurrence, Fate, and Transport of (NDMA) in California
Groundwater" -- by Sally McCraven and Phyllis Stanin of Todd Engineers, and Dr.
Quanlin Zhou of Lawrence Berkeley National Laboratory will be presented by Sally on
Tuesday, May 20, 2008 at the
Battelle's Sixth International Conference on
the Remediation of Chlorinated and Recalcitrant Compounds
to be held in Monterey, California.
This paper presents an assessment of the fate and transport
of NDMA in groundwater at five NDMA release sites in California based on assessment
of field observations.
Laboratory studies indicate that the degree of NDMA
bioattenuation is affected by the initial concentration of NDMA released and the presence
of an adapted biocommunity.
Field data support this finding and suggest that the degree
of NDMA biodegradation in groundwater is highly site-specific.
-- March 2008
Phyllis Stanin has coauthored a paper with CDM and the Monterey Regional Water
Pollution Control Agency on the complexities of recharging recycled water in a
groundwater basin used for potable supply.
The results of their groundwater
replenishment project to date are presented at the
WateReuse Association's 2008 California
Section Annual Conference
in Newport Beach, California on March 25, 2008.
-- March 2008
Effective November 1st, 2007 Todd Engineers has moved to a
new, larger space at the Legacy Alameda Center in Alameda.
We're still conveniently located in the San Francisco Bay area in close proximity
to the Oakland, San Francisco, and San Jose airports.
Our new address is:
2490 Mariner Square Loop, Suite 215
Alameda, California 94501-1080
phone: 510/747-6920
fax: 510/747-6921
-- November 2007
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Linda Spencer
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Linda Rejoins Todd Engineers as Senior Geologist
Combining the multiple perspectives of consultant, water supplier/manager, and
regulator, Linda offers an integrated approach to groundwater basin management.
Most recently, Linda served a variety of positions with the San Francisco Bay Regional
Water Quality Control Board (RWQCB) including Assistant Executive Officer and
Watershed Management Initiative Coordinator.
She is recognized for instituting the RWQCB Groundwater Committee, which fosters an
integrative overview of groundwater quality protection.
Under her leadership, the Committee produced innovative strategies for groundwater
protection and beneficial use designations in San Francisco Bay groundwater basins.
Linda also served on the staff of Alameda County Water District and worked previously
for Todd Engineers in the 1980s.
Her early work at the Illinois State Water Survey was one of the nation's first
statewide projects for mapping out groundwater protection zones.
She also served two terms in 2000 and 2001 as the President of the San Francisco Bay
branch of the Groundwater Resources Association.
Linda brings more than 15 years of specialized experience in hydrogeology,
water quality, groundwater basin management, and regulatory compliance.
-- October 2007
Todd Engineers is seeking a
full-time Staff Engineer.
-- October 2007
Edwin Lin of Todd Engineers is the lead author for a new article entitled
A New Method to Evaluate Polydisperse Kaolinite Clay Particle Removal in
Roughing Filtration Using Colloid Filtration Theory.
The article, which will be published in an upcoming issue of the
academic journal Water Research, presents the establishment of a new method for
predicting the fate and transport of suspended solids through deep-bed, granular filters (or
roughing filters) that incorporates recent advances in trajectory modeling.
Roughing filters are an integral part of many drinking water treatment systems in the
United States and around the world and, in combination with slow sand filters, represent
a promising method for improving the quality of source waters to allow for sustainable Aquifer
Storage and Recovery (ASR) in siliceous aquifers.
In addition to broadening the application of trajectory modeling to real-world applications
this research lends insight into the fate of suspended solids in the near-well environment
in ASR wells.
Edwin conducted the laboratory experiments in cooperation with The Australian Commonwealth
Scientific and Industrial Research Organisation (CSIRO) Land and Water as part
of his M.S. degree in Groundwater Hydrology at Flinders University of South Australia.
Currently, the article can be viewed at
http://dx.doi.org/10.1016/j.watres.2007.08.018.
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Particle size distributions (PSD):
(a) 2.18mm media, 4 columns, 0.5m/h, 700NTU;
(b) 7.55mm media, 4 columnds, 1.0m/h, 700NTU.
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-- October 2007
David Keith Todd, the founder of Todd Engineers, was a pioneer and strong proponent of
artificial recharge and conjunctive use of groundwater storage. We are proud to carry on that
tradition, working with DWR and local water agencies to make it real.
Phyllis Stanin and Edwin Lin, representing Kennedy/Jenks/Todd LLC,
have worked closely over the past year with staff of Mojave Water Agency and
Bighorn-Desert View Water Agency on a study of potential artificial recharge in the Mojave Desert.
The study was partially funded by a DWR grant administered through the
AB303 Local Groundwater Management Assistance Act.
The study included the development of a basin conceptual model and assessment of water supply
and demand for three High Desert groundwater basins: the Ames Valley, Johnson Valley, and
Means Valley basins.
These basins have been relied upon as the sole source of water supply for
several High Desert communities.
However, projected water demand increases are expected to
stress limited groundwater resources in the near future.
Objectives of the study were to identify the potential need for imported water in the region
and evaluate the feasibility of implementing a
managed aquifer recharge (or MAR) project using State Water Project water to increase the
region's water supply reliability into the future.
The project demonstrated the need for imported water in one the basins evaluated, the Ames
Valley basin.
To assist in the delineation of subsurface lithology and impacts on groundwater
flow of local faults, a field investigation involving high-resolution surface geophysics was
conducted.
Overall, the study identified a target site in the Ames Valley basin for a future MAR
project.
The study has been summarized in a presentation, "Storing Water in California Desert
Basins: Selection of Managed Aquifer Recharge Sites in the Ames Valley Groundwater Basin",
authored by Edwin Lin and Phyllis Stanin with Anna Garcia and Lance Eckhart of Mojave Water Agency.
Edwin Lin presented the paper at the 3rd Symposium in Groundwater Resource Association's
Water Resource Series, Increasing Groundwater Storage to Meet California's Future Water
Demand: Challenges and Solutions held June 20-21 in Long Beach, CA.
-- June 2007
William E. Motzer, Ph.D., P.G., Senior Geochemist with Todd Engineers, has been elected U.S.
Section Councilor for 2007 for the Society for Environmental Geochemistry and Health (SEGH).
Established in 1971, SEGH is an international organization providing a forum for
scientists from various disciplines to work together in understanding the interaction between
geochemical environments and the health of plants, animals, and humans.
SEGH members represent expertise in diverse scientific fields, such as biology, engineering,
geology, hydrology, epidemiology, chemistry, medicine, nutrition, and toxicology.
SEGH membership is international with regional sections to coordinate activities in Europe
and the Asia/Pacific zone.
Dr. Motzer has been a SEGH member for more than 15 years.
The society publishes a quarterly journal, Environmental Geochemistry and Health,
containing articles that include original research papers, research notes, and reviews across
the broad field of environmental geochemistry.
More information can be found at
www.segh.net/journal.htm.
-- June 2007
Two important water management objectives are coming together at a former sand and gravel
quarry in Scotts Valley, California.
The Scotts Valley community seeks to control stormwater runoff and destructive peak flows
in Carbonera Creek and to maximize recharge to groundwater, which is the primary source of
municipal supply.
Raymond Will and Edwin Lin of Todd Engineers have worked with a developer (Standard Pacific),
the City of Scotts Valley, and Scotts Valley Water District to plan a stormwater detention
and groundwater recharge facility.
The facility will be located at a site with permeable sediments but also challenging
topography.
The site, an old sand and gravel quarry on a rugged mountain hillside, is being considered for
development of a mixed residential and commercial complex.
The City and the Scotts Valley Water District have encouraged maximum onsite
infiltration of stormwater runoff to mitigate the impact of the development on the surface
water and groundwater systems.
Site investigations and test work were the basis for water balance computations and evaluation of
alternative methods and their feasibility for construction of an onsite stormwater
detention/recharge facility.
A team of engineers, geologists, and planners has completed a
preliminary design to maximize groundwater recharge incorporating best management practices
at this very challenging site.
Ray Will summarized this project to the American Institute of Hydrology's Annual Meeting and
International Conference entitled Integrated Watershed Management: Partnerships in Science,
Technology and Planning, which was held April 22-25, 2007 in Reno, Nevada.
-- June 2007
The new WateReuse publication,
Investigation of N-Nitrosodimethylamine (NDMA) Fate and Transport,
presents the findings of a multi-year study of NDMA in the environment from both
industrial and wastewater sources.
The study was funded by the WateReuse Foundation and participating water and
wastewater utilities and included researchers at Todd Engineers, the University of
California (UC) at Berkeley, UC Riverside, and Arizona State University.
The publication is available for purchase at the foundation's website
www.WateReuse.org/Foundation/researchreport.htm.
NDMA is a polar compound commonly found in municipal wastewater and is also a
contaminant associated with the aerospace industry.
NDMA in wastewater has the potential to enter potable water supplies when
wastewater effluent is used for landscape irrigation or groundwater recharge.
The California Department of Health Services (DHS) has established a notification
level for NDMA at 10 nanograms per liter (ng/L).
The project included an examination of existing groundwater data as well as
experimental studies to assess the potential for biotransformation and field
studies to assess volatilization and transport of NDMA in irrigated soil plots
and soil columns.
Todd Engineers' work focused on NDMA fate and transport in groundwater based on
assessment of existing data at five sites in California where NDMA has impacted
groundwater including the San Gabriel Basin, the Montebello Forebay,
the Talbert Barrier, Rancho Cordova, and the West Coast Basin Barrier
(see figure at right).
Todd Engineers' study concluded, in part, that NDMA is generally persistent and
mobile, showing little evidence of sorption or biodegradation in groundwater.
Todd Engineers staff contributing to the study included Phyllis Stanin,
Dr. William Motzer, Sally McCraven, and Jesse Crews.
-- August 2006
Todd Engineers (Dr. William E, Motzer, Sally McCraven and Phyllis Stanin)
and Santa Clara Valley Water District (Thomas Mohr) published a paper entitled
"Stable and Other Isotope Techniques for Perchlorate Source Identification"
in the March 2006 (Volume 7, Issue 1)
Environmental Forensics
journal.
The paper presents techniques for using several stable isotopes to fingerprint
perchlorate sources, possibly differentiate perchlorate plumes, and determine
release dates.
The ubiquitous use of perchlorate in solid rocket fuel, munitions, and
pyrotechnics in the latter half of the 20th century led to the release of
these salts to the environment and to numerous instances of surface water
and groundwater contamination.
In addition to man-made sources perchlorate can also occur naturally in
the environment, particularly in certain caliche-derived formations and
in other evaporite deposits.
Techniques discussed in the paper include the use of stable isotopes of
chlorine (37Cl),
oxygen (18O),
strontium (87Sr/86Sr)
and
deuterium (D or 2H).
Other isotopes useful for perchlorate source identification include radiogenic
tritium (T or 3H)
and daughter product
helium-3 (3He)
to age-date relatively modern groundwater.
-- April 2006
The third edition of
Groundwater
Hydrology
by David K. Todd in collaboration with Larry W. Mays was published
in July 2004 by John Wiley & Sons.
This new enlarged edition updates the second edition of 1980,
the most widely-used book in the field with translations into
six languages.
The third edition adds numerous example problems, case studies,
problem sets for student use, and more than 300 new figures and
photographs.
An entire chapter is devoted to presentation of groundwater modeling
using the MODFLOW program of the U. S. Geological Survey.
Groundwater contamination by chemicals receives expanded coverage,
new references at the end of each chapter are given for research
and graduate study, and web sites for hydrologic data and information
are listed for U. S. Government and non-governmental sources.
-- July 2004
