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Black Sediment in Well Water – Causes & Fixes

Updated on September 6, 2022

Common Causes of Black Sediment in Well Water

Mineral Deposits

Mineral deposits are usually the culprit behind well water problems. Every well owner has seen stains on plumbing, toilets, bathtubs, and appliances. Iron and manganese are the common reasons behind black sediment in well water. Iron and manganese are essential for human health, but high insoluble concentrations result in black sediment.

Calcium & magnesium can also give a black color to your water. These minerals are also responsible for hard water stains and scale buildup on your appliances. These two, accompanied by iron and manganese, give your water a blackish look and a metallic taste.       

Silt & Sand

Silt & sand can add brown/black sediment to water. These contaminants tag along the water when it moves over rocks and soil.

Silt & sand are suspended particles and usually settle at the bottom of the well. Private wells with a powerful well pump or a pump too close to the well’s bottom often face issues due to silt/sand pumping. It is also dangerous for your well pump and water tank.

Soil & Mud

Soil & mud enter your well in the same way as silt & sand. However, they can also find their way into your well through broken well cap or damaged well casing. Moreover, a well pump sitting too close to the well bottom can also result in soil & mud contamination. Soil & mud add brown/black sediment to your water.

Black Sediment in Well Water – Causes & Fixes

Organic Matter

Organic matter like leaves, twigs, and tree branches can find their way to your well’s bottom through underground channels. These entities soon decompose and release black debris in the water, which is pumped to your faucets.

Decomposed organic matter can also have a different color than black. Decomposing organic matter also makes your water smelly and undrinkable. It can also clog the well pump and well tank.

A New Well

Constructing a new well shakes up sand, silt, dirt, rocks, and minerals in the ground. These elements find their way into well water for a few days in case of a newly built well.

The good news is that black sediment will stop coming into the water in a few days. You can use bottled water for 3-4 days after building a new well.

Damaged Well

Black sediment in well water can also happen due to a damaged well. An old well with a damaged casing often delivers water rich in sediment and impurities. If you live in an old house and frequently witness water quality problems, it is time to get your well inspected for damages. Ensure you hire a certified well contractor for well assessment or maintenance tasks.

Sewage Contamination

Black sediment in water due to sewage contamination is the most severe and dangerous cause. Private wells dug without following the well construction rules are at higher risk of sewage contamination. The contamination chances are even higher when there is a septic tank, agriculture site, or animal dump near your well. Damaged drain pipes near a water well can leach human waste into water, and rains can sink the wastes further underground.


Every appliance has rubber pipes, and most rubber pipes are black. The rubber in these pipes starts to melt and dissolve as hot water passes through them. The rubber particles can enter your water pipes, and you may notice black sediment in well water.

How to Identify Black Sediment Cause in your Well Water?

There are various reasons behind black sediment in well water. You cannot select a treatment method unless you know what’s causing it..

The first step in identifying the reason behind black sediment is to get your well water tested. You can either test the water at home using a test kit or send out a sample to a certified laboratory. The Environmental Protection Agency (EPA) recommends testing private wells annually to ensure healthy water quality.

Also Read: Gray Well Water [Causes & Solutions]

Fixes for Black Sediment in Well Water

Sediment Filter

Most private well owners usually install a whole house sediment filter. A sediment filter catches suspended particles like sand, insoluble iron, debris, hair, dirt, and sand in well water. The filter traps the contaminants in a mesh when water passes through it. Clean water moves out of the filter, and the trapped particles are periodically flushed out of the filter using a flush valve.

Sediment filters come as standalone systems or as a part of multi-stage filters and lasts 2-3 years because the mesh can be washed and reused. A sediment filter mostly solves the black sediment issue.

Recommended Sediment Filter: SpringWell’s Spin Down Sediment Filter

SpringWell’s Spin Down Sediment Filter

It is the perfect solution to remove black sediment from the well water. The filter captures large chunks from well water and provides sediment-free water. It has a 100-micron rating. Black sediment is usually large and requires a bigger micron rating.

The filter is packed in a transparent housing to help you flush out the accumulated sediment. It delivers water at a 25 GPM flow rate and has 1-inch in/out connections to reduce pressure drops.

Iron Filter

Install an iron filter to remove black sediment if it is due to iron, manganese or hydrogen sulfide. You can find iron filters as standalone or part of a multi-stage filters. Standalone filters are recommended for concentrations above 6 PPM.

A standalone iron filter uses the air-injection system to oxidize iron and remove it with a filtration media. The filtration media is then replaced after some time. Some filters use KDF media to capture iron, manganese, and other impurities in water. KDF filters also need cartridge replacement after 4-6 months.

The filtration capacity varies from one filter to another. Standalone filters can remove iron & manganese up to 15 PPM and 8 PPM hydrogen sulfide from well water. KDF filters (part of whole house filters) can remove iron & manganese up to 3 PPM.

Recommended Iron Filter: SpringWell’s Whole House Well Water Filter System

SpringWell’s Whole House Well Water Filter System

SpringWell’s whole-house iron filter is best for private wells with iron up to 7 PPM, 8 PPM hydrogen sulfide, and 1 PPM manganese. The system comes with a digital Bluetooth-enabled control head to manage the settings.

The system oxidizes the contaminants, which are then captured by the filtration media and removed during backwash. You can program the unit for daily or metered backwash. The whole-house iron filter can be paired with a UV purification system, RO filter, or a salt-based water softener.

Water Softeners

A water softener is best for softening water and removing black sediment if it is caused by calcium and magnesium. Please note that only salt-based water softeners can remove black sediment from well water. Salt-free or water conditioners will choke when exposed to water rich in sediment.

Some states have banned a salt-based water softener owing to environmental concerns. Make sure you check local laws before buying one.

Recommended Salt-Based Water Softener: SpringWell’s Salt Based Water Softener System

SpringWell's Salt Based Water Softener System

SpringWell’s salt-based water softener is an ideal machine for removing black sediment and hardness from well water. The ion-exchange process removes calcium & magnesium from well water and adds sodium or potassium.

Most of the Black sediment is removed by a sediment filter often installed before a water softener, and the remaining is removed by the softener. SpringWell’s softener comes with a separate brine tank for easy maintenance. It features a Bluetooth-enabled control head to manage backwash, change valve settings, and view water usage.

Fixing your Well

So, what to do if the well contractor identifies problems with your well? Get it fixed. You can assign the same contractor or get quotes from others for the best price. Make sure you get all the problems fixed, like repairing the well casing, well cap, well pump position and well screen.

You may need to start extensive repairing work if you have a collapsed well. Mostly, digging a new well is a better option than repairing a collapsed well. You can plug and abandon the collapsed well. Check & follow local codes before structural changes to your well system.

Septic System

If there is a leak in a septic tank or drain pipes, get them fixed immediately. You’ll need professional help for this task. So make sure you hire an experienced well contractor.

Well water contaminated with sewage or septic waste is a serious issue and must be addressed immediately. You must stop using water contaminated with sewage instantly and arrange bottled water for drinking and cooking. Moreover, you must not bathe, shower, wash dishes, or do laundry if your water is contaminated with sewage or septic waste.

Frequently Asked Questions

Is black sediment in well water harmful?

It depends on the reason. Mostly black sediment is harmless, but if it is due to sewage or septic contamination, you must stop using water immediately and fix the problem first.

Is it normal for private wells to have sediment?

Yes. Many private well owners report black or other colored sediments in the water. However, the problem can usually be fixed quickly and easily.

Why is there red sediment in well water?

Red/orange or brown sediment is due to insoluble iron in the water. You can install a sediment or iron filter to remove it from your water. Iron below 0.3 mg/L is safe in the water.

Why is my water filter turning black?

Your water filter cartridge may turn black due to various reasons. It can be due to sediment buildup, bacteria, or an expired filter. Always inspect your filter occasionally and replace the cartridge timely to avoid water quality and flow rate problems.

Why am I suddenly seeing black sediment in well water?

It can happen due to various reasons. Your well may have collapsed due to a broken well casing. Some wells face sediment problems after heavy rainfalls or floods because groundwater seeps into the well. You must discuss this with a private well contractor to get the problem fixed as soon as possible.

Why do I see black sediment instantly after replacing a filter cartridge?

After replacing a filter, the black particles you see in the water are carbon particles or debris on the filter surface. Ensure you run 1-2 gallons of water after every cartridge replacement. Do not waste this water. Use it for gardening or other chores around the house.

Can a RO filter remove black sediment from well water?

Yes. RO filters are highly effective filters against all contaminants, but a standard RO system is usually installed for drinking purposes. It cannot handle the whole house’s water requirement. Large-scale RO systems are available but are extremely costly and require high maintenance levels. Hence, most homeowners prefer a sediment or iron filter, or water softener to remove black sediment from the well water.


  • Roy Jones

    Roy lives in Anderson, Texas, and has been a part of various certified well drilling firms. He has extensive 20 years of working experience in water wells maintenance, repair, and drinking quality. Roy has been guiding neighbors on well issues and writes to educate private well owners about various well water issues.

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