1. Question:
The following submission with questions was received regarding the Kalamalka
Lake Water Source:
In
preparation for the October 22 Agenda I posed two questions asking how many
days over the past four years were the entire Greater Vernon domestic water users on the Duteau Creek Source and how many days on the Kal Lake Source.
The
reply was:
i.) Duteau Creek Treatment Plant was shut down for a period of
four (4) days in 2013 Due to increased turbidity.
ii.) Kal Lake Treatment
Plant was shut down for a period of one hundred (100) days, one (1) day to repair
a burst pipe and two (2) days for maintenance. The plant was closed for ninety
seven (97) days due to increased turbidity.
Of the ninety seven (97) days of
closure due to increased turbidity, thirty three days in 2013 were
due to milfoil rototilling as well as a number of
days in early 2015 for the same reason.
The balance of the closure days was due to spring run-off.
It
is well known that for most of the year Kal Lake raw water is virtually
drinking water quality requiring very little treatment. On the other hand
Duteau Creek water source requires a very high degree of costly treatment (with
more being proposed).
Staff notes to the statements above:
As a water utility, GVW and the authors of the MWP are
bound by the BC Drinking Water Protection Act to meet Provincial standards at
all times. TM7 completes the analysis necessary to assess if Kalamalka Lake raw
water meets Provincial standards, which is the subject at the SAC meeting on
December 3, 2015. As an additional note, each turbidity event listed in the
Question Paper 1 would normally require a public notification (Water Quality
Advisory or Boil Water Notice); however, since we shut dowm MHWTP and relied
fully on DCWTP a water quality notice was not required. Public notification
causes hardship to a community
(stress to customers, increased treatment costs at a customer
level, negative view of the community by visitors impacting tourism, etc.) and
are expensive to manage for a water utility (increased notification and
laboratory costs, dramatic increase in overtime wages, resource allocation to
respond to operational issues and public taking staff away from regular duties, etc.).
My
questions are:
2. Question: With
the milfoil-rototilling program being confined to the north end of Kal Lake
would it not be possible
to move the domestic water intake pipe further out into Kal Lake to avoid the fallout
from rototilling?
Answer: Milfoil-rototilling
is an extremely beneficial service that the Okanagan Basin Water Board (OBWB)
provides to our community. Without it, Kal Lake and the local beaches would
become overgrown with milfoil resulting in a loss to community recreation and
tourist attraction. The extra plant life in the area would also increase the
turbidity and organics in the Kalamalka Lake intake, therefore there are additional benefits
to GVW as a water purveyor. OBWB staff indicate that all the milfoil
must be rototilled to control its growth, hence,
rototilling should not be isolated to certain areas.
Notwithstanding the benefits, milfoil-rototilling operations has been acknowledged to impact the Kalamalka Lake intake water quality.
In response, GVW staff have been
working closely with OBWB and FLNRO (who operate the Kalamalka Lake weir to
Vernon Creek) to reduce the impact and are developing operations plans to
address this and issues being examined are:
·
Impact
to water quality and area being rototilled (OBWB rototillers have installed a
gps on their rototillers and location is being correlated to water quality impacts)
·
Assessing
impacts on water quality when the weir discharging to Vernon Creek is open
verses when its closed. When it’s open, flow from Coldstream Creek flows
directly into Vernon Creek and does not reach the intake.
·
Rototilling timing - there is some conflict between
what is the best time for GVW and the time that is best time for OBWB which
we are currently working through. OBWB’s work window is October 15 to April 1
and the rototiller is shared between Wood Lake and Kalamalka Lake. Wood Lake is more likely to freeze over in early winter; therefore OBWB prefers to start their rototilling on Wood Lake or they
may not get a chance if the lake freezes. However, during this window the weir
is open and turbidity flows to Vernon Creek. The outflow is controlled by the
Province and is shut down near the end of December for fishery purposes. An
alternative time is when the water quality in Kalamalka Lake is naturally poor
(freshet) and there is a high risk that this source must be turned off anyways;
however, this is getting late in OBWB’s season and they prefer completing in
colder temperatures for better die off of the
milfoil.
·
GVW
has been participating in a study in partnership with the District of Lake
Country and MFLNRO since 1997. This study includes water sampling at various
depths and is being conducted Larratt Aquatics. The sampling period of the
study is completed during the growing season (May - November) due to safety
issues thus there is water quality monitoring from December to April. It can
only be speculated that the turbidity would be less if the intake
was extended further
and deeper in the lake,
however, there is evidence
that when the lake is fully mixed (no thermal
stratification) and the weir is closed, the flow
from Coldstream Creek can impact
the water quality
at all depths examined and at times, impact the deeper depth of 30 m
more during large freshet events.
·
Currently,
from an operations point of view, it is a relatively easy task to shut off the
Kalamalka Lake intake and service everyone with Duteau water during the times
that OBWB rototills, especially when it is a planned
shutdown. When OBWB is rototilling, the operations staff are fully aware of the potential water
quality impacts and communicate frequently with our municipal operations
partners and OBWB. The turbidity and UVT trends are watched closely and as the
trend for increased turbidity and/or reduced UVT occurs relatively slowly, the
intake is usually shut off before operational parameters are exceeded. This
avoids middle of the night or weekend alarms with overtime as all operations groups
(GVW, Vernon and Coldstream) and management have a role to play in decision making and turning
valves. The switch in water sources is relatively easy from an operations
perspective but must be completed in a coordinated fashion and customers must be notified.
3. Question: By
increasing the intake distance further out into Kal Lake it would also increase
the depth, would this not negate most of the spring run-off?
Answer:
Heather Larratt’s study showed an improvement to water quality if the
intake was located at 30 or 40 m in depth
instead of the current depth of 20 m (see Table 1 below). However,
when the spring freshet is large, the 30 m depth is impacted more than
the 20 m depth. See plume diagram Attachment
“A”.
It was recommended that if GVW considers increasing the intake
that they also keep the ability to draw from the 20 m depth as well when the 30
m intake was impacted. The current intake pipe may result in insufficient
suction pressure for the pumps to operate at maximum day demand and cannot be
simply extended to the 30 m intake depth. Based on this, two configurations could occur, keeping
the current 20 m intake operational and installing a separate
larger intake pipe to a depth of 30 m. The study also investigated building a
tower with the new intake that has the ability to take water from various depths.
Nonetheless, even though there
are benefits of deepening the intake depth,
it is not guaranteed that GVW would never
have water quality
events on this source or that filtration could be avoided long term and hence the MWP recommended that the money would be better spent
on filtration to meet the IH
water quality objectives on a continuous basis.
Table 1 – Kalamalka Lake: Water Quality Parameters for Various Depths
Kalamalka Lake 2000-2014
|
North 20
m
|
North 30
m
|
North 35
mǂ
|
North 40
m
|
Distance to pumphouse* m
|
315
|
680
|
900
|
1590
|
Average temperature oC
|
6.3
|
5
|
4.7
|
4.5
|
# of seiches over 2 oC/yr
|
10
|
4
|
2
|
1
|
Max seiche temperature fluctuation oC
|
11.7
|
9.9
|
7.5
|
4
|
pH
|
8.09
|
8.00
|
8.07
|
7.97
|
Hardness
mg/L
|
171
|
173
|
184
|
172
|
Total calcium mg/L
|
37.5
|
37.9
|
39.9
|
37.6
|
Total organic carbon mg/L
|
4.7
|
4.7
|
4.1
|
4.7
|
Chlorophyll-a ug/L
|
1.9
|
1.5
|
1.1
|
1.2
|
Turbidity
NTU
|
0.88
|
0.58
|
0.49
|
0.49
|
UV Transmissivity %
|
90.2
|
90.5
|
91.0
|
90.9
|
Avg algae counts cells/mL
|
60
|
92
|
113
|
174
|
E. coli cfu/100 mL
|
<1-270 span="">1-270>
|
<1-40 span="">1-40>
|
<1-1 span="">1-1>
|
<1-1 span="">1-1>
|
Total coliforms cfu/100mL
|
<1-3700 span="">1-3700>
|
<1-530 span="">1-530>
|
<1-19 span="">1-19>
|
<1-1000 span="">1-1000>
|
4. Question:
Would a deeper intake pipe all but eliminate the possibility of contamination and clogging
from a possible Zebra Mussel infestation?
Answer: No, once Kal Lake is impacted by
Zebra or Quagga mussels an increased depth of the intake would
not eliminate the
issue of clogging. The following
is a statement from the University
of California, Center for Invasive Species Research, see link at: http://cisr.ucr.edu/quagga_zebra_mussels.html
“Where quagga and
zebra mussels co-exist, quagga mussels appear to outcompete zebra mussels, and
quagga mussels can colonize to depths greater than those achieved by zebra
mussels and are more tolerant of colder water temperatures. For example, in
Lake Michigan, zebra mussels made up 98.3% of mussels
in 2000, by 2005 quagga mussels represented 97.7% of collected mussels. Zebra mussels were found at
densities of around 899 per square meter, but quagga mussels now dominate at
7,790 mussels per square meter. Quagga mussels have been found at depths of up
to 540 feet in Lake Michigan where they filter feed year round.”
The following link provides further
information on the risks from zebra and quagga in the Aquatic Invasives! A Menace to the West
produced by the Oregon Sea Grant: http://seagrant.oregonstate.edu/sites/default/files/invasive-species/toolkit/zebra-quagga-
5. Question: Why GVW is appear not to be attaching any
priority on this situation?
Answer:
The question goes beyond the terms of reference for the committee;
however, we will provide an answer. As shown in the answers above and in the
assessment completed in TM7, it is
apparent that GVW has been “putting a priority” on this option for many years
now with an 18 year on-going
study and more recently the Kalamalka Lake Assessment Plan. The following is a link to the Kalamalka Lake
Assessment Plan and other work completed in the Duteau and Kalamalka Lake
watersheds: http://www.rdno.ca/index.php/services/engineering/water/greater-vernon-water/watershed-
source-assessments-and-protection
6. Question:
(Question
has been reworded slightly to provide clarity). There appears that there is a
discrepancy in TM3 as it states that “it is predicted that GVW will face
increased water supply shortages in the future unless storage is increased to
support the predicted growth in the domestic sector.” Then in Table 2 of the TM3 summary, the
following is stated:
>2052
|
Okanagan Lake License
|
50,000
|
50,000
|
N/A
|
N/A
|
Good
|
And then TM3 also says “Other small transfers from within the same watershed are much more feasible such as transferring BX
Creek, Coldstream Creek and other small licenses to either Kalamalka Lake or
Okanagan Lake.”
Staff
assumes the question is if GVW is at risk of increased water shortages unless
storage is increased and there is a good chance that a license can be obtained
for Okanagan Lake by transferring licenses, then why are we not doing this?
7. Question: (Question has been
reworded slightly to provide clarity). Within TM5 there are the three numbers
presented: $80.9 million, $137.2 million and $619.6 million. Why the huge
discrepancy between these three numbers?
Answer: Each number represents something different as follows:
·
$80.9 million is the amount that must be spent in
order for GVW to install the pipes necessary
to twin the distribution system
and achieve full separation of the potable
and non potable
(agricultural) systems. It includes the projects in Table 7-1 of TM5 that are
not yet constructed ($63.8 M) in addition to transmission main twinning ($17.1
M) that is required to support fully a separated system for a total of $80.9M.
·
$137.2 million represents
the replacement costs of a fully separated agricultural distribution
system (pipes only). This would include the $80.9 M that must still be
spent to construct the pipes necessary and the infrastructure (pipes) that
currently exists in the GVW distribution
system that can be used for the separated system (valued at $57 M). In other
words, if GVW were to construct a
fully separated distribution system (pipes only) from scratch to service its
agricultural customers, it would cost $137.2
M.
·
$619.6 million represents the replacement costs for the entire
GVW distribution system (pipes only) and includes the domestic and
agricultural system. In other words, if GVW did not exist and a water system
had to be built to service all GVW customers
to the current level of service (pipes only), it would cost $619.6 M to do so.
The
costs in the three points above only looked at pipes (mains and transmissions)
and did not calculate the value of other infrastructure required to operate a
water system, such as pump stations, PRV stations,
reservoirs, tanks (enclosed reservoirs), service mains,
etc. If these items had been
included in the valuation of the above estimates, the costs for each would have
been much higher.
8. Question:
When
comparing 2013 and 2014, what percentage of the total revenue for water was base rate revenue and what percentage
was consumption revenue?
Answer: Question 8 and 9 goes beyond the terms of
reference for the committee, a discussion of rates and revenue is addressed by
the Greater Vernon Advisory Committee (GVAC) and the RDNO Board as part of budget
discussions and did not form part of the work scope of the MWP and hence, is not within the terms of
the SAC mandate to discuss or make recommendations. However, we will provide
an answer. It is assumed
the question is around the ratio between
the infrastructure base fee and the metered consumption fees. The
following provides the percentage of that ratio calculation but does not
include agricultural allocation fees, interest income, grants, meter sales,
construction/development fees, etc.
·
2013
Actuals – base 53.1%; consumption 46.9%
·
2014
Actuals – base 54.0%; consumption 46.0%
·
2015
Budget – base 54.8%; consumption 45.2%
9. Question: “Are base rate revenues and consumption revenues
maintained in separate
accounts”?
Answer: Yes, rate revenues
and consumption revenues
are tracked in separate general
ledger (GL) accounts.
"Waiting for someone to ask why ag lines haven't been separated from domestic lines," offers Kia.
No complaints from agriculture obviously!
If lines were twinned, there'd be nobody to subsidize agriculture's water rates...or lines.