Looking to plumb in the Londinium I, and seeking opinions for an appropriate softening/filtration system.
Relocated to Dubuque from Chicago, where my LaSpaz was plumbed in since new to the standard softener/carbon filter system from Chris Coffee. Just plugged that system in on arrival. I've been running the Londinium (acquired since relocation) with Pavlis'ed distilled in the tank, but now want to direct plumb it to add the flexibility of variable pressure via regulator on the inlet.
Water analysis numbers from municipality below, and actual test from my tap and spaz forthcoming next week.
So, what say you wiser-than-I water chemists? What is the proper water correction based on what you see in these numbers?
Thanks in advance for any and all insights.

________________________________

The City of Dubuque Eagle Point Water Plant is a lime softening plant. We reduce the hardness of the raw water from 290 mg/L hardness (as Calcium Carbonate) to approximately 100 mg/L. The Total Dissolved Solids of our finished water is approximately 160 mg/L.
Here is a list of compounds and the levels found in our water:
Arsenic <0.005 mg/L
Barium 0.37 mg/L
Cadmium <0.005 mg/L
Chromium <0.005 mg/L
Lead <0.0025 mg/L
Mercury <0.001 mg/L
Selenium <0.005 mg/L
Silver <0.01 mg/L
Copper <0.0100 mg/L

pH 9.3
Alkalinity 60 mg/L
Total Hardness 100 mg/L
Calcium Hardness 35 mg/L
Mg Hardness 58 mg/L

Fluoride 0.7 mg/L
Chloride 17.2 mg/L
Nitrate 0.3 mg/L
Orthophosphate 0.8 mg/L
Sulfate 23.8 mg/L
Iron < 0.1 mg/L
Manganese <0.1 mg/L
Potassium 2.2 mg/L
Sodium 13.8 mg/L
Zinc <0.1 mg/L

This is an excellent example of hard water that has been treated at the utility with slaked lime softening. They essentially reduced the calcium and the carbonate by adding calcium hydroxide to the water, which depleted the dissolved CO2, raised the pH, and caused a lot of calcium carbonate to precipitate out giving you a much lower calcium hardness and alkalinity than the raw aquifer water. You end up with a relatively high proportion of magnesium hardness in the tap water.

The total hardness of 100 mg/L would ordinarily indicate a need for softening. But the calcium hardness of only 35 mg/L makes it far less scale prone than the total hardness would imply. You can do a Langelier Saturation Index calculation on this water and come up with a pHs at 130℃ of about 6.9 That indicates that at that relatively high boiler temperature, water at a pH of 6.9 or lower should tend to dissolve rather that deposit limescale. A common way of predicting boiler pH for theses calculations is to use the Puckorius pHeq based on the alkalinity number, which for this alkalinity level is around 7.2. So you get an LSI in the ballpark of 0.3, which indicates slight if any scale. (Consult Jim Schulman's Insanely Long Water FAQ for more about LSI calculations.)

I think you can plumb this system in with a simple particulates plus a carbon block or charcoal filter. You would want to check it for scale accumulation and descale if/when necessary.

Your chloride ion, at 17 mg/L is higher than you might prefer -- any chloride may be corrosive, and La Marzocco advises that if it's above the 30 - 50 mg/L you should consider removing it with an RO treatment system. Synesso's advice is the most conservative - they like to see it below 15 mg/L. I don't see it as a cause for alarm here provided you avoid a treatment system that reduces alkalinity and acidifies the water. In other words, avoid any hydrogen ion exchange resins (also called WAC resins, decarbonizing resins) like the BWT bastmax, Mavea Quell, Everpure Claris. In my opinion, because of your moderate alkalinity and borderline chloride level, a conventional softener that exchanges sodium ions for hardness ions (and does not reduce your alkalinity) would be best if you do decide to soften.

If you wanted to be safely in the never-descale zone, and not go to remineralized RO, then you could consider conventional softening - i.e., a strong acid cation (SAC) softener that replaces hardness ions with sodium or potassium. Your CCS 10" softener would work here or the Homeland cartridge from Clive. (In a reservoir machine you might even use a Rocket/Bilt/Oscar pouch filter.) The conventional softeners will reduce your total hardness (both the magnesium hardness and the calcium hardness) and keep all the alkalinity, which you want to have in the face of that borderline chloride. Also will add a little sodium to the water but not enough to affect taste.

Pat, I really appreciate your taking the time to review, and your thoughtful, thorough response. I shall sleep better now knowing the water in my "newish to me town" is pretty well sorted to begin with. Cheers!

Pat,
In light of your analysis above, would you consider the below an appropriate treatment solution for my coffee bar sink (just to faucet, not to machines)? Seems like it is in the spirit of your recommendation?

waterdrop ub

I think I like the clive homeland solution for the Londinium I. The single cartridge; included pressure regulator; and purge line make it an attractive, plug and play solution, albeit with somewhat pricey filter cartridges.
Thank you again!
Jason

jtbenson wrote:I think I like the clive homeland solution for the Londinium I. The single cartridge; included pressure regulator; and purge line make it an attractive, plug and play solution, albeit with somewhat pricey filter cartridges.

If you don't use a lot of water and replace the filter at its 6 month interval the homeland would be pricier.

If you use over a gallon per day your filter replacement cost would be more comparable. The Clive HWCS treats 1700 grains, and the CCS generic 10" softener treats only 850 grains. For your 100 mg/l total hardness (5.85 grains per gallon) the CCS would exhaust the softener in about 145 gallons and the HWCS in about 290 gallons.

Both are old fashioned SAC resin softeners, will replace the calcium and magnesium in your water with sodium ions. And leave the alkalinity unchanged, which is good. Also will not reduce your TDS reading (it may go up slightly.)

sorry, either i forgot the link to the 'waterdrop ub' system I was referring to in regards to faucet only water, or it got edited out...

so, here's a follow-on question:
is it not recommended to supply more than one machine from a single filtration system? (never seen the bowels of a commercial setup.)
just thinking out loud here, but I already have a softener/carbon filter supplying one machine. could i install a jg two-way divider on the outlet side of the system and supply a second machine from the same filtration system? i'm guessing pressure may be reduced too much for this to be viable, but would love to hear opinion/experience.

jtbenson wrote:sorry, either i forgot the link to the 'waterdrop ub' system I was referring to in regards to faucet only water, or it got edited out...

I didn't see that when posting my previous reply. That's looks like a good quality filter for removing even fine particulates, along with activated carbon and KDF for chlorine, chloramine, off tastes and odors. Of course it will leave hardness, alkalinity, chloride, TDS all unchanged. Fine for drinking and brewing. As mentioned earlier, simple filtration like this would be OK in an espresso machine with your water if you keep an eye out for long-term scale accumulation.

jtbenson wrote:so, here's a follow-on question:
is it not recommended to supply more than one machine from a single filtration system? (never seen the bowels of a commercial setup.)
just thinking out loud here, but I already have a softener/carbon filter supplying one machine. could i install a jg two-way divider on the outlet side of the system and supply a second machine from the same filtration system? i'm guessing pressure may be reduced too much for this to be viable, but would love to hear opinion/experience.

I'm not the person to ask about plumbing issues like this, but I will say that people do tee off the filtration system to two machines. The concern is that the supply flow rate from the filter system is adequate to feed the supply flow requirements of all machines. And it can be helped along with an accumulator tank if necessary. Here's an old post with some discussion related to that: Water input flow and pressure for La Marzocco GS3 and Linea Mini