One thing is that is critical on a municipal water supply is a chlorine filter.
Not if the municipality uses chlorine as the disinfectant. The chlorine will rapidly gas off upon heating to strike/sparge temp, and even to quite a bit less than this. Of course, any water used on the cold side definitely needs to be chlorine-free.
Sorry, I didn't see this and several people requested my response.
Sure, chlorine does volatilize relatively quickly at room-temperature and more quickly at higher temp. But the problem is that the chemical reaction between malt compounds and chlorine compounds is almost instantaneous. If there are ANY chlorine compounds (aka: chlorine or chloramines), they will instantly react and create chlorophenols in your wort that will NEVER volatilize off.
So if you're going to play this form of Russian roulette with your beer, there had better be only chlorine in your tap water and your heating duration had better be long enough to allow ALL the chlorine to volatilize out of the water before that water touches your grist. Be aware that there's typically several ppm of chlorine in tap water to provide disinfection. While wort doesn't produce a 1 to 1 ratio of chlorophenols per ppm of chlorine compounds, I can assure you that chlorophenols can be tasted in beer when they are present in the several ppb range. So your water HAS TO be virtually free of chlorine compounds or you may end up with chlorophenol problems in your beer.
If you want to assure better beer, please ignore the advice above.
Far be it from me to disagree with the water master, whose posts I always appreciate and learn a great deal from, but I’m not suggesting that anyone play Russian roulette with their beer. Again, if your city uses chlorine gas, as mine does, year-round, then simply heating it to (in my testing) ~140 or higher will remove 100% of the chlorine gas (caveat: my water comes in at ~1ppm, so this is the max I've tested with). You don’t even have to maintain it at that temp for any length of time. All the chlorine is gone by the time you reach that temp. And if you heat to 165 for striking, even more so. No one seems to be arguing against this, including Martin. Sounds to me like the trepidation is because there is doubt that 100% of the chlorine gas gets removed? It does for me.
Take my advice or not, but ignoring it in no way assures better beer. All it assures is more equipment and more steps on brew day. If you can confirm that your city uses chlorine gas, I’m simply suggesting you try this, if you're inclined. It’s very easy to test for yourself whether or not I’m spewing nonsense, and you might find your brew day simplified. I dispense my water from a drinking-safe hose (drinking safe--that's important!) from the hose tap straight into the kettles. I’ve done this for years now. My beers have won quite a few awards, including my American lagers. There has never been even the slightest trace of chlorophenol in my beers.
I started down this road when the brewery I was brewing at had the water filter break, and no one realized it for a month. We had been brewing with unfiltered water all that time. The beers turned out fine. And then at home, I used to filter, but I didn't realize how slow the filtration rate needed to be to remove all the chlorine. On a whim I tested the post-filter water with strips and realized that the water in the kettles that still had a lot of chlorine in it...and yet the beers were turning out great. Why weren't they loaded with chlorophenol? Because all the chlorine gas was disappearing upon heating. It dawned on me that I could save some time and hassle on brew day by no longer filtering. Oh--I have a water filter for sale, best offer takes it!