Chandos Water Quality

Chandos-Water-Top


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last update: 15 June 2017

Introduction

Water Quality is usually assessed based on various factors, such as clarity, health safety, chemistry, life forms supported, anthropogenic pollution, salinity, acidity, temperature.

This section is under construction, but here is a start….

Trophic Status

The Trophic Status of a lake refers to the level of nutrient enrichment and the attendant water clarity as affected by algae and weeds.  The main nutrients that affect the biological productivity of the lake are phosphorus and nitrogen. An oligotrophic lake is nutrient poor and the clarity is very high.  A lake with a eutrophic status is nutrient rich, usually weedy, and has very little clarity.

For a  very thorough and readable backgrounder on Trophic Status, see the Ontario MOE handbook  87-lakeshore-capacity-assessment-handbook-en-1.  In particular Technical Bulletin No. DESC-4 on page 95.

On the trophic scale, Chandos is borderline oligotrophic-mesotrophic, with Secchi depths around 5m, phosphorus in the 10 µg/L range, and Chlorophyll a (chla) around 3 µg/L.  (Chla concentration is a measure of planktonic biomass)

trophic-status-chart

Phosphorus

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Phosphorus

From Mike White’s 2006 paper: MikeWhite klsa phos report
“Phosphorus is found in both soluble and insoluble forms, which together account
for the total phosphorus (TP) in a lake ecosystem.   The insoluble forms occur
predominantly from dead or decaying organisms (leaf litter, aquatic macrophytes, phytoplankton, zooplankton, etc.) and eventually falls to the lake bottom, while the  soluble forms stay suspended in the lake water column. Soluble phosphorus is comprised of numerous complex compounds; however, a proportion is soluble reactive phosphorus (SRP). SRP is readily used (absorbed) by phytoplankton and macrophytes and thus increases lake productivity.
Almost all natural sources of phosphorus (~90%) enter a lake system in the insoluble form, whereas, phosphorus from anthropogenic (human induced) sources are predominately of the soluble form(~90%) (Mackie, 2001). This means that phosphorus entering aquatic systems from human sources is immediately available for primary production. The insoluble phosphorus, which has fallen to the lake sediment, can be converted to soluble form and is not trapped there permanently.
The mobilization process can be quite complex, but in its simplest form insoluble phosphorus can be reduced to a soluble state at the sediment-water interface through decreasing redox potential and pH levels. These conditions exist when lake sediment oxygen levels decrease and become anoxic (depleted of oxygen). This anoxic condition occurs in lakes when algae die and fall to the lake bottom. As the dead algae are decomposed bacteria consume oxygen and favourable conditions for phosphorus mobilization occur (Mackie, 2001). Thus, once a lake becomes eutrophic (turbid algal state) this negative feedback loop can make restoration efforts challenging.
So what does this tell us?
It is possible to limit anthropogenic sources of phosphorus, creating an initial decrease in levels; however, long-term reduction may take many years as the insoluble phosphorus is mobilized and absorbed by plant species.
The easiest way to restore a lake is to prevent it from becoming eutrophic in the first place.”

(think of trying to “uncook an egg”)

Phosphorus Cycle

(from Wikipedia) The phosphorus cycle is the biogeochemical cycle that describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere. Unlike many other biogeochemical cycles, the atmosphere does not play a significant role in the movement of phosphorus, because phosphorus and phosphorus-based compounds are usually solids at the typical ranges of temperature and pressure found on Earth.

Humans are extreme disrupters of the natural phosphorus cycle, as we mine it extensively  and redistribute it widely. The initial source of phosphorus is rocks and minerals.  It is a very long cycle, and one can hardly conjure the geochronological time and path it would take for a phos atom to make it from living algae back to sedimentary rock and back to algae again.  And along the way this atom may be stuck in some seemingly endless biological sub-cycle before finally escaping and continuing its pilgrimage back to rock.

If you have the time (9 mins),  an entertaining and educational video on the nitrogen and phos cycles can be found here: Khan Academy N & P cycles.   (phos cycle at 5:15)

An easy intro to the phos cycle can also be found here: Phosphorus Cycle,

Phosphorus in South Bay

The role of phosphorus in the trophic state of fresh water lakes is well known.

The chart below shows South Bay phosphorus readings from the epilimnion (top waters) from various sources back to 1981.

South Bay Top Phos chart rev 2.PNG

Some observations and interpretation:

The 1981-82 data with the line through it is MOE data.  See their report chandos-study-1986 .  (1981 table station: CH-3 comp. and the 1982 table “for station CH3 composite Sample”)
It is instructive to notice how much variation there is in  the phos readings over the course of 1981 and 82.  This is a caution not to read too much into limited amounts of phos data.

It does seem like the phos situation is trending down, which is good, and it seems not unreasonable to say that the phos levels in South Bay are in the 8-12 range.  Nevertheless, we should continue to focus on lowering the anthropogenic component.

The lone point (#28 – 5 µg/L ) for the 2014 paleo study at CH3 in South Bay seems low.  The reading at another location in South Bay was 9 µg/L.

Phosphorus in Gilmour Bay

Because of the anoxic conditions at the bottom of Gilmour Bay, there is a marked difference in phosphorus levels from the top to the bottom.  (much higher at the bottom)  This is because in the absence of oxygen, the redox conditions change, allowing certain chemical reactions to take place that result in phosphorus being released from the sediment.

  • In  1981 the bottom phosphorus ranged from 12 to 163 with a mean of 44 µg/L.
  • In 1982 the bottom phos ranged from 15 to 230 with a mean of 94.8 µg/L.
  • In 2014 the hypolimnion (bottom)  phos reading was 140 µg/L.

The following graph shows the data for the Gilmour Bay top waters…

Gilmour Bay Top Phos chart rev 2.PNG

As with South Bay, the Gilmour Bay top water phosphorus can be said to be in the 8-12 µg/L range.

There have been some excellent phosphorus testing and analysis performed on the TSW chain of Kawartha Lakes.  See  Kawartha Lakes Stewards Report 2015

During-season phosphorus variation

Spring phos levels tend to be lower if there is a flushing effect from in-flowing rivers.  Chandos, being a head lake, likely does not receive as great a benefit from its relatively small watershed as do those lakes on the Trent Severn Waterway.

The KLSA have an excellent paper by Mike White  (2006) regarding phosphorus in the Kawartha Lakes:  White report KLSA

Drinking Water

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Drinking Water

As part of the Winter’s Bay condo development planning process, extensive testing was carried out on both lake and ground water to determine their potability and suitability as a drinking and domestic water source.
There are 2 public documents outlining this testing by EXP, along with the results and recommendations. (see links  below)  (There  are several other documents available on line, including a peer review by Stantec.  see here for a list: Winter’s Bay development docs)

Although the EXP information is site specific, it is an excellent starting point for all Chandos cottage owners wanting to know more about their drinking water.

Just be extremely aware that there is no guarantee that the results actually represent conditions at other sites, and also that conditions can change with time.

Radon and Uranium in Well Water

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Radon and Uranium in Well Water
The most startling outcome of the Haastown/EXP water source study was the rejection of drilled well water because of the presence of uranium and radon.

The EXP report recommends using treated lake water instead, which appears to be the route that the developer is taking.

Uranium is ingested and can affect  kidney function.

Radon is a gas, which is released from the water and is inhaled, thereby potentially affecting the lungs. Radon also enters a dwelling through cracks etc in basement.    It is a very complicated subject, as the actual health hazard depends on how much radon is in the home air itself.  eg how much is also seeping into the home from the ground, and what  level of air exchange exists in the dwelling.  Please see the following comments from Public Health Ontario: radon 2.Public_Health_Ontario_-_May_6_2013

Regardless, it seems like a good idea that anyone with a deep drilled well, who lives on the lake year round, should consider having their water tested for uranium and radon. 

See  Tables 1 & 2, pages 12 &13, of the EXP document wintersbay-water-tests7-exp-_-_december_12_2013 ,   for the lake surface water analysis results, (page 12&13)

See  Table 6 on page 145, along with tables C-1, C-1B, C2, C-2B, starting on page 124 of  the EXP document winters-bay-uranium-well-watert-estexphydrogterraianalysmay2012  for the ground water test results, including radon and uranium.

Canada has a max limit (0.02 mg/L) for uranium in well water.  Table 6, p. 145, shows a range of uranium readings, with the highest at Test Well #5 being 0.139 mg/L.  See the Health Canada Document health canada uranium-eng for more on uranium.  It says that reverse osmosis is a remedy.

Canada does not have a criterion for radon in well water,  but some results (max of 410) at Winter’s Bay exceed the proposed US regulatory Guideline of 148 Bq/L.  See the  CDC Radon fact sheet.

 There is a remedy for radon gas, involving aeration at point of entry and venting to the outside.

blue-green toxic blooms

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Cyanobacterial Toxins in  Drinking Water

 First off, we do not have a problem on Chandos with blue-green algal blooms.  However, some lakes in the Muskokas, Haliburton and the Kawarthas  have experienced these toxic blue-green blooms.  And what with global warming, more lakes will soon do so as well.
A clear and present danger from any surface water drinking source is the potential for exposure to microcystins.  These are associated with  blue-green algal blooms.

Under the right environmental conditions, microcystins and other cyanobacterial toxins are naturally formed in water in the environment.  They are produced and stored in the cells of cyanobacteria, and released when the cells rupture or die. Most scientific studies on cyanobacterial toxins focus on microcystins, which are generally regarded as the most important of the freshwater cyanotoxins.

Options available for individual households obtaining their drinking water from a surface water source affected by a cyanobacterial bloom would include switching to an alternative water supply, changing the location of the water intake pipe and installing a drinking water treatment system.  However, the treatment of water supplies for the removal of cyanobacteria and microcystins at the residential scale is complex, and there are no drinking water treatment systems available that are certified for the removal of microcystins.
Please be aware that boiling  does not remove these toxins.
See the Ontario fact sheet on this topic: Ontario fact sheet blue-green algae
And if you  really want to know more, here is an excellent source from the Government of Canada: cyanobacteria-cyanobacterie-eng
.