from the President...
by Teresa Herrera
Spring is here which is the time for new
beginnings and growth. As
so many of us are caught up in the frantic pace of life, this is a
good opportunity to stop, take a deep breath, look around, and
appreciate the signs of life all around us.
The greenness of the hills, the blossoming flowers, the birds
chirping happily away.
Something to be Proud of…
The Bay Section is also experiencing growth and
renewed energy and vitality. I
am pleased to look around at our membership and see so many
dedicated people volunteering their time to this organization.
I recently attended a Northern Regional Committee meeting in
Sacramento where representatives from all the northern local
sections were in attendance. Just
in this meeting alone, the SFBS had the strongest showing of
attendees. One of the
exercises we went through was to figure out how many members in each
section were “active in furthering the mission of CWEA”.
The SFBS group counted 53 people who play an active role in
the CWEA! The other
sections were amazed at this number, as most of them could boast
eight to ten active volunteers.
We here in the Bay Section have made this
Section one that all other sections look to as a model.
Our committee structure, our volunteer pool, our success in
carrying out the mission of CWEA, and the fun that we have in doing
all this makes us a section that we should be proud of.
Let me say that I am extremely proud to be a part of the San
Francisco Bay Section.
Your Bay Section Board of Directors has
recently voted to subsidize a portion of our monthly dinner meeting
costs. What this means
to you is that the cost of all our dinner meetings (with the
exception of our Awards Banquet) will not be more than $25.
It is becoming increasingly difficult to find venues that
charge less than this amount. At
the same time, we recognize that many of our members don’t get
reimbursed by their employers for attending dinner meetings.
So, as a way to keep these meetings affordable and allow the
maximum amount of people the opportunity to network and learn from a
speaker, we decided to subsidize our dinner meeting costs.
With that said, I hope to see many of you at
this month’s meeting. It
will focus on the winner of the Section’s Plant of the Year Award,
Central Contra Costs Sanitary District.
Please refer to the flyer in this newsletter for detailed
information about the meeting.
Until next month, remember to slow down, even
stop, and take the time to appreciate all the beauty that this
season brings. Take
care and be safe.
Mercury TMDL Workshop Shares Latest News
By Bill Ellgas of East Bay Municipal Utility
On January 17, 2001 the Lab Committees for Bay Area Dischargers
Association (BADA) and the SF Bay and Santa Clara Valley Sections of
the California Water Environment Association (CWEA) sponsored a
half-day workshop in San Jose on the SF Bay’s mercury TMDL. The workshop’s purpose was to disseminate information on
mercury collected the year prior to and following the SF Bay
Regional Water Quality Control Board’s letter requiring
dischargers to begin using EPA Method 1631 for mercury analysis in
treated effluents to gather accurate data as part of the mercury
TMDL development process. Four
presentations were given to a group of nearly fifty.
The workshop began with a presentation from Peter Halpin,
Caltest Analytical Laboratory, entitled,
“A Review and Discussion of the Ultra Trace Total Mercury Method
Halpin summarized the sampling (EPA 1669) and analytical (EPA 1631)
protocols, and reviewed Caltest’s methods development and
facilities changes made prior to 1631 certification.
He also discussed instrumentation, analysis notes to maximize
precision and accuracy and minimize contamination, and Caltest’s
experiences since becoming certified.
Mr. Halpin concluded that an autosampler can be reliably used
for 1631 lieu of manual bubblers, 1631 criteria can be met without a
class 100 clean room but he recommends its consideration, and
industrial discharge and influent samples must be diluted or
analyzed by the traditional method, EPA 245.1.
The second presentation, “A Comparison of 1999
and 2000 POTW Mercury Data, Methods & Special Studies,” was
given by William Ellgas, East Bay Municipal Utility District. Mr. Ellgas compiled and analyzed the mercury data from 17 Bay
Area POTWs with average daily flows ranging from 2 to 126 MGD.
The data were generated by both EPA methods 245.1 and 1631,
and collected between January 1, 1999 and December 31, 2000 from
influent, effluent and special QC study samples. The combined effluent flow of 505 MGD from the agencies
surveyed represents 83% of the total POTW and Industry discharge to
the San Francisco Bay. Though
acknowledged as a minor contribution to mercury levels in the Bay,
the RWQCB’s January 24, 2000 draft mercury TMDL proposed a Bay
wide mass limit for POTWs and Industry of 50 kg/year (twice the
current flow of 600 MGD x a concentration goal of 25 ng/L).
Data presented at the workshop compared EPA 1669 sampling
protocols to “normal” sampling procedures to determine any
differences between the two approaches, influent to effluent
concentrations to calculate POTW mercury removal efficiency, and
pre-2000 (245.1) to post-2000 (1631) data to calculate total mass
loading using each analytical method.
The dataset consisted of 614 influent and 593 effluent
samples analyzed by EPA 245.1, and 90 influent and 526 effluent
samples analyzed by EPA 1631. The
following observations were reported:
POTW laboratory QC studies showed that no measurable
contamination difference was observed when “normal” sampling was
compared against the ultra-clean, EPA 1669 sampling protocol.
However, reductions were seen when sampling containers and
equipment were scrupulously cleaned and sample lines regularly
EPA 1631 appears not to be a good method for POTW influent
samples when concentrations of >100 ng/L are present (supporting
Mr. Halpin’s conclusion above).
With an influent to effluent treatment efficiency of >90%,
secondary wastewater treatment is a highly effective means for
removing mercury. Using a mix of data (predominately 245.1 with
some1631) from the 1999 dataset, the total mercury mass from all
Bay POTW and Industry effluents was calculated to be 22.2 kg/year
(extrapolated from 18.7 kg/year).
Using only the 1631 data generated in 2000, the total mercury
mass discharged for all POTW and Industrial dischargers was
calculated to be 11 kg/year (extrapolated from 9.3 kg/year),
one-fifth the proposed TMDL mass limit of 50 kg/year, and half the
value obtained using 245.1 data.
The third presentation of the day given by Guy
Kumar, San Francisco Public Utilities Commission, “Atmospheric Mercury Sampling
and Data Review,” focused on the SF Bay Regional
Monitoring Program (RMP) pilot study on atmospheric deposition and
the data it generated. Mr.
Kumar discussed the scope of the pilot study, the methodology and
instrumentation used, and the data it generated.
Atmospheric deposition is divided into two categories:
1. Wet and dry Direct, that which is deposited directly into
the Bay at the air/water-surface interface, and 2. Indirect, that
which is deposited on the watershed and washed into the Bay during
rainfall events or by other means.
Over the course of the study, mercury concentrations appeared
fairly constant at around 2000 pg/m3 in ambient air taken
at the three (North, Central and South Bay) locations.
Values were seen as high as 4100 pg/m3 and as low
as 1500 pg/m3. Using
the concentration information and the known surface area of the
three Bay sectors, the total mercury mass loading from direct air
deposition for the
entire Bay is estimated at 20.3
kg/year, 8.4 and 8.5 kg/year in the North and South Bays
respectively, and 3.6 kg/year in the Central Bay.
A similar approach used for indirect air deposition
produced an estimated total mercury mass loading of 41.1 kg/year.
The final presentation of the day, “Improving the Haystack by Regulating
the Needles; Mercury in Wastewater and Watershed-scale Process”
was given by Dr. Khalil Abu-Saba, California Regional Water
Quality Control Board, San Francisco Bay Region.
The range of issues Dr. Abu-Saba discussed from his “Big
Picture” perspective included:
The Bottom Line – A proposed mass limit of 50 kg Bay
wide for all wastewater with concentration goals as an annual
average of 0.025 ug/L for deep water dischargers; 0.015 ug/L for
shallow water dischargers; and 0.007 ug/L for the lower South Bay.
Compliance is proposed to be regulated by mass not
Mercury concentrations in sediment are a linear
function of % fines ranging from 0.0 ug/L in sand to 0.4 ug/L in
clay with 100% fines (values up to 1.1 ug/L were found).
Mercury concentrations in water are a linear function
of suspended sediments.
“The Fly in the Ointment” – Methylation of
mercury is considered to be the real problem; methylmercury is the
form that bioaccumulates and can be magnified up to ten million
times at the top of the food chain.
Some information on the TMDL timeline: by 2004
adopting control measures in the Basin Plan; 2004+ adopting criteria
for methylmercury and mercury in fish