Water treatment specified from a test, not from a sales visit

Start with a test

Water treatment is the area of plumbing most prone to being sold rather than specified. A system fitted on the strength of a free in-home test and a persuasive conversation frequently addresses the wrong problem, or a problem you did not have.

The right sequence is straightforward. Get an independent laboratory test. Read the results against the actual symptoms you are experiencing. Then specify equipment to treat what the test found, sized to your household's flow requirement.

What to test for depends on your supply. On municipal water, your water department publishes an annual quality report, which covers the supply as delivered to the system, worth reading, though it does not tell you what your own plumbing is adding. A test at your tap is useful if you suspect lead from old service lines or interior pipework, or if you have taste, odour or staining problems.

On a private well, nobody is testing it but you. Annual testing for bacteria and nitrate is the baseline, with broader testing every few years covering hardness, pH, iron, manganese, arsenic, uranium and radon depending on your local geology. Your board of health can advise what matters in your town, because it varies enormously across the state.

What Massachusetts water does

The state has enormously variable water chemistry, and the problems cluster geographically.

Low pH, acidic water, is widespread in New England groundwater, particularly in the central and western parts of the state and on wells in granite geology. It is the most under-recognised plumbing problem here because it does its damage invisibly, corroding copper pipe from the inside until pinhole leaks appear. Blue-green staining on fixtures is the tell.

Iron and manganese are common on wells across the state. Iron produces orange-brown staining on fixtures and laundry; manganese produces black specks and staining and is the more stubborn of the two.

Hardness varies from very soft in much of the western uplands to genuinely hard in parts of the south coast and on certain well geologies. Hard water scales water heaters, kettles, dishwashers and shower heads.

Radon in water occurs in parts of the state, particularly in granite areas, and is separate from radon in air.

Arsenic and uranium appear in specific bedrock geologies and are worth testing for on wells in those areas.

Sodium and chloride from road salt affect wells near heavily salted roads, which in Massachusetts is a great many of them.

Which of these you have depends on where you are and, on a well, on your specific bedrock. That is precisely why testing beats assuming.

Hardness and softeners

Hard water is dissolved calcium and magnesium. It does not harm health, but it scales the inside of water heaters and boilers, blocks shower heads and aerators, leaves spotting on glassware and fixtures, reduces the effectiveness of soap and detergent, and shortens appliance life.

The standard treatment is an ion exchange softener, which swaps hardness minerals for sodium and periodically regenerates itself using salt. It works, it is well proven, and its trade-offs are worth understanding.

It adds sodium to the water, which matters to anyone on a sodium-restricted diet, potassium chloride is an alternative regenerant at higher cost. It consumes salt and water during regeneration, which is a recurring cost and a discharge that in some Massachusetts municipalities and on some septic systems is subject to restriction. And it needs a drain connection and a brine tank that has to be kept filled.

Sizing is by hardness level and household water use, and modern demand-initiated units that regenerate based on actual consumption rather than a timer use considerably less salt and water than older clock-based models.

It is normally sensible to leave one cold tap, usually the kitchen, unsoftened for drinking and cooking, and outside taps unsoftened for the garden.

Iron, manganese and staining

These are the most common well water complaints in Massachusetts and the treatment depends on the form the iron takes, which is why testing matters so specifically here.

Clear water iron is dissolved and invisible at the tap, turning orange only after standing or contacting air. Low levels can be handled by a softener; higher levels need oxidation and filtration.

Red water iron is already oxidised and visible as particles, and needs sediment filtration.

Bacterial iron produces a slimy reddish deposit in cisterns and toilet tanks and needs shock chlorination as well as filtration.

Manganese is harder to remove than iron, causes black staining and specks, and generally needs oxidising filtration with the correct media.

Typical treatment approaches are an oxidising filter, an aeration and filtration system for higher concentrations, or chemical oxidation followed by filtration in difficult cases. What matters practically is that these systems need backwashing, which requires adequate flow and a drain, and the media has a finite life.

Note that iron and manganese also foul well pumps, pressure tanks and pipework, so treatment protects equipment as well as laundry: see well pump repair.

Low pH and copper pipe

This one deserves emphasis because the consequence is expensive and the fix is comparatively cheap.

Acidic water, anything much below neutral pH, dissolves copper from the inside of supply pipes. The process is gradual and invisible until pinhole leaks start appearing, typically in the same house within a short period of one another because the whole system has been exposed equally. Blue or green staining in sinks, baths and on fixtures is the visible warning.

By the time pinholes appear, the pipe wall has thinned throughout and the honest answer is usually repiping. Treatment before that point protects the entire supply system.

The standard treatment is a neutralising filter containing calcite or a calcite and magnesia blend, which raises pH as the water passes through and dissolves gradually, so the media needs topping up periodically. Where correction needs to be more precise or the pH is very low, a soda ash injection system is used instead.

One side effect worth knowing: neutralising with calcite adds hardness, so a house with very acidic water sometimes ends up with a neutraliser followed by a softener. That is a normal and correct arrangement rather than over-specification.

If you are on a well with copper pipe and have never tested pH, that test is the highest-value one on this page.

Bacteria, UV and radon

Bacterial contamination on a well requires immediate attention. A positive coliform result means the well is not sealed against surface water, or something has contaminated it. The response is shock chlorination, investigation of the cause, a failed well cap, a cracked casing, surface water ingress, or proximity to a failing septic system, and retesting. Fixing the cause matters more than the disinfection, because otherwise it recurs.

UV disinfection is the standard ongoing protection where bacterial risk is present. Water passes a UV lamp which inactivates organisms. It is effective, chemical-free and low maintenance, with two important requirements: the water must be clear, because turbidity and iron shield organisms from the light, so pre-filtration is essential; and the lamp needs annual replacement regardless of whether it is still glowing, since output declines well before it fails.

Radon in water is treated by aeration, which strips it out and vents it outside, or by granular activated carbon for lower levels. It is a separate issue from airborne radon and needs its own test.

Arsenic and uranium require specific treatment technologies matched to the form present and the concentration, and this is genuinely specialist territory where the test result drives everything.

Filters, sizing and running costs

Whole-house sediment filters are the simplest and most useful basic addition on a well, catching grit and particulate that would otherwise wear pump seals, foul valves and block aerators. They need cartridge changes, and the interval tells you something about your water.

Point-of-use filtration, under-sink carbon or reverse osmosis at the kitchen tap, is the sensible approach for drinking water quality issues, because treating five gallons a day is far cheaper than treating everything that flushes a toilet. Reverse osmosis produces excellent drinking water, uses some water in the process, and needs membrane and filter replacement.

Two practical points that catch people out. Flow rate and pressure. Every filter and treatment vessel creates some pressure drop, and a stack of undersized equipment can noticeably weaken the whole house. Sizing must account for peak simultaneous demand, not average use: see water pressure problems.

Running cost. Salt, media replacement, cartridges, UV lamps, membranes and the water used in backwashing and regeneration all recur. Ask for the annual figure before buying, because it varies enormously between technologies and it is the number that determines whether a system stays maintained. A treatment system nobody services is worse than none, because it becomes a stagnant obstruction in the supply.