Bolinas Community Public Utility District
A Special Meeting Of
The Board Of Directors
March 07, 2012 270 Elm Road, Bolinas
1. Call to Order.
Directors Amoroso, Kimball, Siedman and Smith present;
director Bender attending by telephone. Director Siedman presiding.
3. Community Expression.
4. Mesa Park Ballfield Irrigation and Public Restroom Project:
Approve Revised Project Budget; Approve Revised License for Use of Irrigation
Directors Siedman and Amoroso met with Bryan Lee and Patricia
Hickey of Mesa Park recently to discuss the revised project budget and license
agreement and the Mesa Park Board approved both documents at its meeting
on March 5, 2012. In response to a question from Stacey Henderson,
director Siedman explained that the matching funds for the project budget
are from a variety of sources, including the County of Marin, Maggiora &
Ghilotti, as well as $144,000 in funds for the sewer lateral connection for
the bathrooms from the Firehouse & Clinic project.
K. Bender/B/ Kimball all in favor
to approve the revised project budget for the Mesa Park Ballfield Irrigation
and Public Restroom Project.
Director Siedman noted that the Board determined it was
necessary to revise the license agreement to address comments from nearby
property owner Bob Cart and to provide the district with flexibility in connection
with its water supply study. Director Amoroso added that the license
also needs to reflect that an additional use of the water by Mesa Park will
be to flush the public toilets to be installed near the ballfields.
In response to questions from Stacey Henderson, director Siedman explained
that a meter will be installed at the irrigation well to monitor usage and
that the 14,800 daily use amount was established on the basis of the storage
capacity of the water tanks at Mesa Park. Discussion ensued about specific
language to revise sections 1(a) and 1(b) of the license agreement.
D. Smith/B. Kimball all in favor
to approve the license agreement, as revised.
5. Water Supply Augmentation Project: Discuss Study of
Potential Water Supply Sources.
Director Siedman noted that Rob Gailey, a licensed consulting hydrogeologist,
is present to talk with the Board on how to proceed with its planned study
of potential water supply sources which, at present, is specifically focused
on groundwater in light of the installation of the Mesa Park irrigation well
discussed in the previous agenda item. The question presented for the
district is whether there is the potential to augment the district’s potable
water supply with groundwater sourced from district property. Director
Smith commented that he is interested in understanding the aquifer and how
it might behave over time, particularly given the proximity to the ocean
(and the fact that the well is far below sea level in depth) and climate
change predictions indicating the future may present protracted droughts.
Rob Gailey began his remarks by noting that the issues to be evaluated with
regard to the groundwater on BCPUD property include both the quantity of
the groundwater and the quality of the groundwater. He noted that in
some cases it is possible to obtain a lot of groundwater from a well, but
the quality is bad and therefore treating the water to acceptable standards
can be very expensive. As for the hydrogeology of this particular aquifer,
he suggested the Board to envision the BCPUD property on which the well is
located as a swimming pool: if the pool is filled with sand, and water
is then poured in, the water will fill the gaps between the sand particles.
If a well is installed into the “swimming pool” and the water is pumped out,
the water level in the pool will drop. If it rains, the water in the
pool is recharged and, if the ground around the pool slopes toward the pool
(as the BCPUD property does), then even more water can shed into it and recharge
the pool. The difficulty is calculating or predicting the precise recharge
rate as some of the water runs off or evaporates .
Rob then suggested that the Board envision that one of
the side of the swimming pool is removed such that the sand filling the pool
is connected directly to the sand surrounding the pool on one side. In this
instance, the water recharging the pool is going somewhere, perhaps discharging
to a surface body of water such as the Bolinas Lagoon or the ocean.
As such, if some of the water in the “pool” is intercepted via well pumping,
then the dynamics of that system is being disrupted which raises the concept
of “safe yield”, or the amount of water that can be withdrawn without
undesirable effects. On a related note, Rob explained that the
groundwater in contact with the porous sand medium has its own chemical nature;
in effect, as it remains in the ground it takes on character of the solids.
Hence, water quality will vary depending on the sediments in which the water
Rob stated that it is his opinion that the use of the
well by Mesa Park does not have the potential for undesirable effects (and
he stated as much in an opinion letter that he provided in connection with
the district’s CEQA analysis for the project). The question now is:
how much more water is there? Rob said his best conceptual model to
discuss this is the three-sided swimming pool, where the headwall of the
valley is toward the intersection of Mesa and Olema-Bolinas Roads.
Rob noted that Mesa Park first attempted to install an irrigation well near
Mesa Road toward Overlook Road; the drilling company went down 70 feet and
the shavings came up too hot to hold and bone dry, meaning that the soil
below consisted of tightly compacted material unlikely to produce water.
As such, that side of the valley is tantamount to a concrete wall.
Rob said it is similarly unlikely that the other two sides of the swimming
pool (one parallel to Mesa Road and the other is the Francisco Mesa) will
pass very much water. If so, then the source of recharge for the irrigation
well is rainfall that concentrates and runs down there.
Rob suggested that the district can monitor the existing well in operation
to obtain more data or perhaps install a test hole to do so. He commented
that the water quality of this well is not very good: the hardness
in quite high, as are total dissolved solids, iron and manganese. As
a result of this relatively high mineral content, the water likely does not
taste good. Director Smith inquired if the district could do something
relatively simple, such as install a pressure transducer in the well, to
evaluate the impact on the water level in the well of the pumping by Mesa
Park (by evaluating the water level when the pump is off). Rob agreed
this would be a viable means by which to evaluate how the aquifer is responding
Stacey Henderson said she had heard that there were two
aquifers tapped by the well. Rob reviewed the well log and said it
wasn’t clear, but this isn’t a typical aquifer; he said he does a lot
of work in the Central Valley and based on his experience, the well log indicates
that this area of Bolinas does not produce a lot of water. In response
to questions from director Amoroso, Rob noted that the district staff performed
a short well test in the field which suggested the well would produce at
perhaps 15-20 gallons per minute. Director Amoroso noted that this
was far less than the rumors he was hearing in town of the well producing
100 gallons per minute; he said that the district wants to determine the
potential for the groundwater as cost-efficiently as possible.
Director Siedman asked if Rob has a specific protocol
to recommend for the district to evaluate the groundwater. Rob said
that a protocol will depend on the district’s cost considerations with respect
to treating the water (which, as noted above, can be very expensive) as well
as water quantity determinations. As for the quantity of water, Rob
said that if he had to guess, he thinks it is unlikely that there is much
water in this relatively little valley as it does not have a big catchment
or permeable sediments.
Stacey Henderson noted that the district has had a moratorium in place for
40 years due to a genuine lack of water; given that, she feels it is imperative
for the district to determine whether there is any water to be had for the
community from this well. She agreed that it needs to be cost-effective.
Director Amoroso noted that the district is in violation of the chlorine
disinfection byproduct rules when it uses its reservoir water supply; as
such, the district should determine whether groundwater could be the district’s
back-up water supply rather than the reservoirs (which could be reserved
solely for firefighting). In addition, more water might mean that the
district could lift individual water restrictions that have been placed on
many of the district’s customers.
Rob said that if one assumes that water treatment is going to occur (to address
the quality of water issue), then the issue to evaluate first is quantity
in order to decide whether it is worthwhile to proceed further. He
said that a thorough pumping test and the installation of 2 -3 monitoring
wells might be the first next step in order to look for boundary effects
and determine the overall size of the aquifer. Each well would need
to be at least 80-feet deep and he estimated the cost at approximately $10,000
per well (fully burdened). Discussion ensued about the length of time
period to monitor the well (to account for both wet and dry years) and other
approaches such as the installation of a pressure transducer. Rob agreed
that the installation of the pressure transducer would be a logical next
step given the district’s emphasis on cost-effectiveness and its willingness
to spend the time needed to evaluate the resulting data. In response
to a question from director Smith, Rob said that the district also can perform
periodic general mineral chemistry panels to test the quality of the water
over time as Mesa Park pumps the well. Rob commended the Board for
considering all issues carefully and proceeding efficiently in light of the
uncertainties going forward.
At the conclusion of the meeting, there was Board consensus to install a
pressure transducer in the existing well, proceed with the Mesa Park irrigation
project and monitor the response of the aquifer to the pumping of well water
for that project. After an adequate time period sufficient to evaluate
the well water supply and quality during a continuum of environmental conditions,
a decision will be made to determine next steps, if any, to further evaluate
the potential of this aquifer as a source to augment the district’s potable