Ward reports for my water, Bear Gulch Water District (on the SF Peninsula)

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wuertele

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I live in the Bear Gulch Water district (on the SF Peninsula), but the report I get from the supplier does not have enough information to tweak my water recipe. So this month I had my water tested by Ward Labs.

Most of the San Francisco Peninsula from Menlo Park up to the City gets their water from the SF Municpal Water District, which gets it from a man-made resevoir in the Sierra Mountain Range called Hetch Hetchy. If you live on the San Francisco Peninsula, it is likely that your water is exactly the same as mine, so you might find this data useful.

In fact I took four samples using different methods, and had all of them tested. The methods were:

1. Sample A: Filtered Tapwater. I broke in a new activated carbon filter, then sampled some water passed through it.
2. Sample B: Unfiltered Tapwater. I sampled some straight tapwater.
3. Sample C: Tapwater plus campden tablet. I tapped 10 gallons, smashed in half a campden tablet, and waited 30 minutes, then sampled.
4. Sample D: Tapwater plus campden tablet, passed through brewing system. I passed the 10 gallons of campden-treated water through my brewing system (without adding any heat or other ingredients), then took a sample from my fermenter.

The results of having these samples tested by Ward Labs are here. I also included a record of the report from my water supplier, the California Water Service Company.

I think this water is pretty good. I've never tasted tap water as good as mine. And it seems pretty flexible when it comes to brewing. I just got a pH meter, and this weekend I made a Schwarzbier and measured the pH 15 minutes into the mash, it came out 5.4. I don't have my recipe handy but I'll document all that and post it later.

If anyone can think of other information I can provide about Bear Gulch water, please let me know!
 
Sure looks like mostly snowmelt to me.

It's a lot softer than Denver's water, and you don't even have to "tap the Rockies."
 
It seems like there is a lot of discrepancy between Calcium levels reported by California Water Service vs. Ward Labs.

Do you trust the Ward Labs results more so than the California Water Service?
 
The Ward Labs results are typical Hetch Hetchy reservoir results. Straight out of the Sierras, it has very little mineralization.

The differences in the concentrations between the Ward results are not significant and they are the same water. I note that the potassium does inch up with the Campden addition. That suggests that the tablets are potassium metabisulfite and not sodium metabisulfite. All results are reasonable and expected.

I would not trust the Ca Water Service result since its not clear what source they tested. I suppose it may reflect the worst water quality they expect to deliver?
 
I just recently had my water tested. I live in San Francisco. I ran water from faucet in my garage through carbon filter. Didn't do anything else.

It appears as though the water is even more "pure" then when measured in 2009. What time of year did you take samples Wuertele?

To date I have only be adding Gypsum to my water to get the calcium levels bumped up a bit. I'm going to start playing around with my water chemistry. It is nice to have such low mineral content as a starting point. It almost seems like it would be a waste to invest in a reverse osmosis system like I was thinking of doing.

pH 8.9
Total Dissolved Solids (TDS) Est, ppm 74
Electrical Conductivity, mmho/cm 0.12
Cations / Anions, me/L 1.1 / 1.2

Sodium, Na 11
Potassium, K < 1
Calcium, Ca 8
Magnesium, Mg 3
Total Hardness, CaCO3 33
Nitrate, NO3-N 0.6 (SAFE)
Sulfate, SO4-S 4
Chloride, Cl 6
Carbonate, CO3 9
Bicarbonate, HCO3 28
Total Alkalinity, CaCO3 39
Fluoride, F 1.13
Total Iron, Fe < 0.01
 
I just recently had my water tested. I live in San Francisco. I ran water from faucet in my garage through carbon filter. Didn't do anything else.

It appears as though the water is even more "pure" then when measured in 2009. What time of year did you take samples Wuertele?

To date I have only be adding Gypsum to my water to get the calcium levels bumped up a bit. I'm going to start playing around with my water chemistry. It is nice to have such low mineral content as a starting point. It almost seems like it would be a waste to invest in a reverse osmosis system like I was thinking of doing.

pH 8.9
Total Dissolved Solids (TDS) Est, ppm 74
Electrical Conductivity, mmho/cm 0.12
Cations / Anions, me/L 1.1 / 1.2

Sodium, Na 11
Potassium, K < 1
Calcium, Ca 8
Magnesium, Mg 3
Total Hardness, CaCO3 33
Nitrate, NO3-N 0.6 (SAFE)
Sulfate, SO4-S 4
Chloride, Cl 6
Carbonate, CO3 9
Bicarbonate, HCO3 28
Total Alkalinity, CaCO3 39
Fluoride, F 1.13
Total Iron, Fe < 0.01
 
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