What's in Guste Island water

Madisonville, St. Tammany Parish · PWS ID LA1103189

The short answer

Guste Island water is soft, about 0.8 grains per gallon, chloramine-disinfected groundwater. The recommendation for this water: a sediment prefilter when suspended material is confirmed at the house, a whole-home catalytic carbon filter, manganese filtration, plus optional reverse osmosis at the kitchen sink.

Chloramine is easier to miss than chlorine because its smell is less obvious. Guste Island water carries chloramine at 2.5 parts per million, and it tests soft at 14.1 milligrams per liter, about 0.8 grains per gallon. For perspective, chloramine in drinking water typically runs from 0.5 to 2 parts per million. This reported level is above that range and equals about 63% of the federal maximum. Unless a pitcher or refrigerator filter specifically lists chloramine reduction, do not assume it removes it. The published report also shows manganese at the aesthetic limit.

Chloramine is easier to miss than chlorine because its smell is less obvious. 8 grains per gallon.

Why this is the recommendation

What you may notice in your waterBeneath the surfaceWhat gets your attention?

Why it is easy to miss

Chloramine can be present without a strong smell

The report confirms chloramine in this water even if you do not notice the obvious pool smell associated with chlorine. Ordinary pitcher and refrigerator filters should not be assumed to reduce it unless chloramine is specifically listed.

A faint chemical taste or odor, or no obvious warning at all
Skin that feels tight or dry afterward
Hair that feels dry or harder to manage
Water, coffee, or tea that tastes off

What leaves a mark

The staining has a measured source

Iron and manganese can leave orange or dark marks in tubs, sinks, fixtures, and laundry. Treatment built for those metals goes ahead of the rest of the system.

What this report does not rule out

PFAS cannot be seen, smelled, or tasted

This report does not include a usable PFAS result. No result is not the same as no PFAS. Certified kitchen reverse osmosis reduces PFOA and PFOS in the water used for drinking and cooking.

Your water report

Your water reportGuste Island

Magnolia - Guste Island (CSWR) · PWS ID LA1103189 · 2025 water quality report

chloramine at 2.5 ppm, above the typical 0.5 to 2 ppm range · Made to last longer and often less noticeable than chlorineCatalytic carbon removes it throughout the house

hardness at 0.8 grains per gallon · Already soft water, with no hardness problem to treatNo softener recommended

manganese at the aesthetic limit · Orange or dark stainingManganese filtration is built for exactly this

Chloramine is made by combining chlorine with ammonia. It lasts longer than chlorine and can be much less obvious at the tap. The staining in tubs and laundry comes from the manganese in the report, and filtration built for it takes it out.

Water system boundaries interlock around here, so we confirm yours by address before we quote anything.

What we'd install

Based on the report, whole-home catalytic carbon for the chloramine at every tap. Sediment can vary house to house in the Madisonville area. If we find grit or suspended material at your tap, a whole-home sediment prefilter goes first in the treatment line. Manganese filtration handles the staining before it reaches your fixtures. Reverse osmosis at the kitchen sink is optional, for drinking water and coffee. The whole-house recommendation remains the catalytic-carbon system either way.

**Sediment prefilter**Added when grit or suspended material is present

**Manganese filtration**Built for the staining in tubs and laundry

**Reverse osmosis**Drinking water at the kitchen sink

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What this does for your home

Reduces chloramine throughout the house, including showers and the water used for coffee, tea, and cooking
Built to remove the iron and manganese behind the tub and laundry staining
No unnecessary softener for water that already tests soft
Filtered drinking water from its own kitchen faucet

Cutaway of a water heater with sediment settled at the bottom

Easier on the parts that wear out

Sediment settles in your water heater and lowers its efficiency, and chlorine and chloramine embrittle the rubber seals, gaskets, and hoses inside your appliances over time. Filtering the whole house is gentler on all of it.

U.S. Dept. of Energy Energy Saver; ASTM D6284.

Source: Magnolia - Guste Island (CSWR) annual water quality report. PWS ID LA1103189, verifiable in the EPA Safe Drinking Water database →Figures are as published by the system; see the original report for sampling methods and ranges.The published report reviewed for this page does not include a usable PFAS result, so this page does not claim that PFAS are present at this address.Get my written plan and price →

Clear at the faucet does not show you the trip it took.

Before water reaches your glass, it travels through the public distribution system, your service line, and the plumbing inside your house. These are the surfaces people never see.

Corroded supply line removed from the founder's Covington home — A corroded supply line removed from Shawn's own Covington home.

Illustration of rust and mineral accumulation inside an aging municipal water main — What decades of rust and mineral accumulation can look like inside an aging main. Photorealistic illustration.

You cannot replace every pipe between the source and your faucet. You can put a final treatment barrier where the water enters your home and at the faucet used for drinking.

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The public recordNo violations on record

This Magnolia Water system (Guste Island) has a clean violation record. EPA shows no drinking-water violations as of August 2026. A 2022 state survey noted source and management deficiencies, which are findings, not violations. Its operator, Magnolia Water, is under a Louisiana Public Service Commission investigative audit of its billing and service practices, due February 2027.

EPA ECHO · LPSC Docket U-37584. Public records, current as of August 2026. They update quarterly. Operators: contact us to correct an error.

What this means at your house

Your water arrives with chloramine in it, at 2.5 parts per million. Utilities make chloramine by combining chlorine with ammonia so it remains effective farther through the distribution system. It can be less obvious than chlorine: some people notice a faint chemical taste or odor, while others notice nothing at all. Ordinary pitcher and refrigerator filters should not be assumed to reduce it unless chloramine is specifically listed. Catalytic carbon reduces it before the water reaches the house.

This is soft water. Hardness tests at 14.1 milligrams per liter, about 0.8 grains, and for a family using around 300 gallons a day that puts roughly 13 pounds of dissolved rock through the house in a year. Genuinely hard water runs well past a hundred pounds a year, and that difference is why a softener is not in the package for this neighborhood.

The water here is groundwater, pumped from Guste Island Water Supply Well 1. The report also shows manganese at the aesthetic limit. That is what causes the staining that shows up in tubs, sinks, and laundry over time, and manganese filtration is built for exactly that.

How the report becomes the recommendation

Each finding decides a piece of the package, including the pieces we leave out.

The report shows	At your house	The answer	Why that one
Possible sediment after utility treatment	Grit in aerators, toilet tanks, and small valves	Sediment prefilter when confirmed at the house	Sediment can enter from mains, service lines, or home plumbing, so the annual report cannot tell us whether your house needs this stage.
Chloramine at 2.5 ppm	The taste and smell in coffee, tea, and the first glass of the day	Whole-home catalytic carbon	Chloramine holds together inside plain carbon. Catalytic carbon is processed to break it apart.
Hardness at 0.8 grains per gallon, soft	No scale problem to fix	No softener	The resin would have nothing to grab, so it stays out of the quote.
Manganese at the aesthetic limit	Orange or dark staining in tubs, sinks, and laundry	Manganese filtration	It is built for exactly this kind of staining.

Water system boundaries interlock around here, so we confirm yours by address before we quote anything.

Get the report for your exact address

Tell us your address and we will pull the report for the water system that serves it. You get our recommendation and the price in writing before any work starts, and a licensed plumber handles the install.

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Nearby in Madisonville

← All neighborhood water reports

It cannot say what is causing dry skin at your house. Hot water, soap, weather, and the disinfectant can all contribute, and the report only establishes that the disinfectant is present.

It cannot speak for the pipes inside your own walls. Lead sampling covers a handful of homes across the whole system, and your service line, solder, and fixtures are yours alone.

It says nothing about sediment at your particular faucet; annual reports do not measure what collects in one house.

Before anything goes on a quote, we ask what you are actually noticing and test whatever the published data cannot answer.