Reverse Osmosis
Reverse Osmosis Drinking Water Systems
The most complete treatment available at a single tap — and the right answer for lead and PFAS in Greater Boston homes with older plumbing.
At a glance
Reverse Osmosis- Installs atKitchen sink
- Membrane life3–5 years
- Pre/post filtersEvery 6–12 months
- RemovesLead, PFAS, arsenic, nitrate
Figures are typical ranges for Massachusetts installations. Your system is specified from your own test results.
Why point-of-use still matters when you have a whole-home system
A whole-home filter treats volume: every shower, every wash cycle, every flush. Reverse osmosis treats the twelve or so litres a day your family actually drinks and cooks with, and it treats them far more aggressively than it would be practical or economical to treat the whole house. The membrane rejects dissolved contaminants that carbon alone won't hold — lead, arsenic, nitrate, fluoride, and PFAS compounds. In a Greater Boston home, this pairing is usually the entire correct answer: catalytic carbon on the main line for chloramine, reverse osmosis at the kitchen tap for everything the city's treatment can't control once the water enters your building.
The lead question in older Massachusetts housing
MWRA water leaves the reservoirs essentially lead free, and MWRA treats with soda ash and CO₂ to raise pH and reduce corrosivity — which has cut lead levels sharply since the 1990s. But lead in Boston-area tap water does not come from the reservoir. It comes from lead service lines and from solder and fixtures inside the house, and that is a building-by-building problem in a housing stock this old. Boston's free lead service line replacement programme is worth pursuing if it applies to you. Reverse osmosis at the tap is what controls the rest.
Living with an RO system
A modern under-sink unit fits in a standard cabinet with a dedicated faucet at the sink, and can be plumbed to feed the refrigerator ice maker and water dispenser as well. Pre-filters and post-filters get changed every six to twelve months; the membrane runs three to five years on good feed water. Systems do produce some reject water — modern high-efficiency units have improved that ratio substantially, and we'll tell you the actual ratio for the unit we're proposing rather than glossing over it.
How it goes
Test first. Quote second. Install third.
In that order, every time. It is the only way to know whether you need a three-thousand-dollar system or a two-hundred-dollar one.
Free in-home water test
We measure hardness in grains per gallon, pH, chlorine or chloramine, iron and total dissolved solids at your tap, and look at your plumbing, water heater and any existing equipment. About 45 minutes, no obligation. Where it's warranted, PFAS, arsenic, radon and bacteria go to a MassDEP-certified laboratory — quoted before any sample is taken.
Straight answers, in writing
Every number read against its standard, what it means for your house, and what we'd do about it. Including the cases where the answer is that you don't need anything from us — which in MWRA communities happens often.
Installed, tested, and proven
Licensed, insured, permitted where your town requires it, and sequenced correctly: sediment, oxidation, softening, specialty media, then UV. We re-test after commissioning, because a system nobody verified is a hope rather than a treatment.
Straight answers
Reverse Osmosis — common questions
Does reverse osmosis remove healthy minerals?
It does reduce dissolved minerals along with the contaminants. The dietary contribution of tap water minerals is small compared with food, but if it matters to you, remineralising cartridges are available and we'll fit one — it's a common request and an easy addition.
Can reverse osmosis feed my fridge and ice maker?
Yes, and we'd recommend it. It's a short additional run in most kitchens and it means your ice and dispenser water get the same treatment as the tap. Mention it when we're there and it gets designed in rather than retrofitted later.
Is RO enough on its own for a private well?
No. Reverse osmosis protects one tap. On a well, iron, manganese, hardness, sediment and bacteria are affecting your whole house and will foul the RO membrane quickly if they aren't handled upstream. RO is the last stage of a well system, not a substitute for one.
Free in-home water test
Let's find out whether you actually need this
The in-home test is free, takes about 45 minutes, and ends with a written report — including the parts where the answer is that you don't need anything from us.
- Hardness in grains per gallon, pH, chlorine or chloramine, iron and TDS — measured at your tap.
- PFAS, arsenic, radon and bacteria through a MassDEP-certified laboratory, quoted before any sample is taken.
- Every number read against its standard, in writing, with no obligation.
Request your test
2 minutesWe'll be in touch shortly to confirm a time for your free in-home water test. If it's urgent, call (508) 686-1582 and we'll pick up.