Ask Your Question

Angie's List Answers is the trusted spot to ask home improvement and health questions and get answers from service companies, health providers and consumers. For ratings and reviews on companies in your area, search Angie's List.

Top 30 Days Experts
Rank Leader Points*
1 kstreett 240
2 Guest_9020487 110
3 Guest_9190926 105
4 GoldenKid 100
5 ahowell 95
6 KnowledgeBase 95
7 skbloom 80
8 Guest_98024861 70
9 Guest_9311297 70
10 Guest_9400529 70

*Updates every 4 hours

Browse Projects By Category

Question DetailsAsked on 1/30/2015

Could well water sediment/ tiny old pipe particles stick to the insides of PVC pipes? Could they be flushed out?

We have sediment/tiny rust particles coming thru all water sources into our house. A plumber told us the particles had been building up in our PVC pipes over the 35 years we had well water. Since we switched to city water 1 1/2 years ago & still have the sediment coming thru, he said we needed to run our hot and cold water all the time for 24 to 48 hours from outside faucets to flush out all the stuck particles from the insides of our PVC pipes leading into our house.

Another plumber said that sediment couldn't stick to the insides of PVC pipe & since we have rust particles, we must have some galvanized pipe feeding water into our house. In @ 1978 we know that new PVC pipes were put in to my Mother's house (across the yard from me). At the same time they put in new water pipes to my house and we assumed they were PVC, too. But my Mother has never had the sediment/ dirt I have coming via the water. Thanks so much for your responses!

Do you have the same question? Follow this Question

3 Answers

Voted Best Answer

Excellent response by JCody.

With the exception of vacation homes/cabins with long periods of disuse, I have never seen more than a slight lime or iron algae slime build up or "growing" inside plastic pipes - certainly not flake rust, which has to be coming off something metal. However, if rust and sediment was previously coming in from a well pressure tank or the well itself or outside steel/iron pipe for up to 35 years, then you could have quite a layer lying relatively loose in the bottom of the pipes.

Check with your neighbors to see if any are having the same problem, just on the hapenchance that a public line on your side of the street is metal and rusting out.

As JCody said - if only on hot water side probably hot water heater rusting - drain several gallons out the bottom faucet on the tank (be cautious - hot water) into a white bucket and check for significant rusty sediment accumulation - though if incoming water was dirty, that could just be an accumulation in the tank from that, not a sign of rusting in the tank. Note - for most effective cleaning of water heater of heavy accumulation, shut off gas/power to it, then open drain valve with a hose leading to safe disposal area, then after a minute or so turn off incoming water flow (and outgoing hot water also if has a valve there) till hose goes dry (tank is drained empty), then reopen incoming cold water valve and let run for 5-10 mintues to let the incoming water flush the bottom of the empty tank. Then shut off drain valve, let tank fill, then drain off for 5 minutes or so under pressure again,or till water coming out of hose is clear. Then close drain valve, make sure both inlet and outlet valves at top of water heater are fully open, run some hot water somewhere to clear out the pipe at the outlet valve, then relight gas. If there was not a hot outlet shutoff valve, you will have to go around and open each hot water outlet in the house to drain out the accumulated air (and flush toilets if they use tempered water). Best to disconnect washer and dishwasher and reefer hoses at their shutoff valves and drain some water into a pail to get loosened up junk out so it does not go into the appliances. This is a pretty lengthy process.

There is also one risk with this - if your water heater is old and the bottom of the tank is about ready to break through and is only holding in there because of the sediment cover, sometimes old tanks start leaking within hours or days after this treatment - or sometimes after just regular bottom drainage of 5 gallons or so annually. Not that they are damaged by the cleaning - just because they were on last leg, and cleaning the bottom removed the sediment blocking pinholes, which then open up under the flushing action and the stress of being emptied/refilled.

Until you get rid of where the rust is coming from, not much use flushing the lines or water heater.

The flushing requires every drawpoint be flushed - you need to open up all faucets and run dishwasher and clothes washer (first run should be empty at small load setting with a bit of chlorine bleach in it, as mobilized rust can stain dishes/clothes). About 3-5 minutes of flushing should do it - enough to get good flow to every point in the house.

Outside faucets - be sure to reinsulate the faucets if you have winters in your area.

My first suspicion would be that your "new" water line connected through some old galvanized - maybe they hooked the city water in at the pumphouse and used the old pipe from there to house ? 35 years is right at the age where galvanized pipe would be expected to be significantly rusting to the point of failing.

Potential sources: if you have a drain or faucet near where the pipe comes into the house (or an outside one maybe in the old pumphouse if new water comes through there) run water there to see if the rust/flakes are in the incoming water or is originating in the house. Run water through cheesecloth or old nylon stocking to see the sediment/flakes. Common rust sources, when they are appearing housewide:

1) well screen/casing rusting, or pump drawing sediment in from too low a setting in the well or improper/failed screen

2) pressure tank in pumphouse

3) rusting galvanized, or very old cast iron/ductile iron pipes - in-line from city connection, or maybe if the plastic pipes in your house are replacement ones, maybe some galvanized pipe was left in a hard-to-get-to place.

4) water heater

5) pressure relief tank for water heater - sometimes small 2-5 gallon one inline just before heater, sometimes older ones are large (10-50 gallon), look like a well pressure tank, nestled up in the joists or in a corner somewhere, or even in attic at times

6) rusting water storaqe tank or metal cistern, if your water goes through intermediate storage tank

Unfortunately, probably the easiest way to tell, unless you have an outside faucet on the incoming supply line, is to open up the piping a couple of convenient places to see if there is a layer of rust and sediment in the house lines; and also check the incoming water (maybe put in a dripleg faucet right after the shutoff valve to enable checking without making a total mess) for sediment/rust. If it is coming in with the water, then you could install a rust/iron filter system there for roughly about $250-500 typically and then flush the household lines.

If the sediment/rust is sitting in the household lines, then unfortunately to flush it out you might be able to flush the lines satisfactorily as noted above, but might have to put a pump on the system to increase the flow to a significantly higher rate in the pipes. The theory would be to get the flow velocity up well above anything you will see in normal use to flush out the loose stuff, so under normal flow what is left will not mobilize. Some slight risk of a pipe rupture, say if you take it up to about 100 psi in a normal 30-60 psi system - and you have to bypass any pressure regulator, and isolate ALL water-consuming appliances when you do this to avoid blowing out their seals and hoses - washer, dishwasher, reefer, water heater, boiler, water purification/treatment systems, and toilets with shutoffs (because you can blow out seals), etc. The key is to NEVER be running the pump at high pressure with all faucets closed - open everything up that is going to be flushed first, THEN run the pump to increase flow to flush the system, then shut off pump before closing faucets and such to prevent a sharp pressure buildup. This is an exercise best done with 2-3 observors running around the house checking for possible leaks. Normally, when doing this (cost about $500 plus a few friends/family members as observors)) you would also follow it up with a hypochlorate treatment (like is done with new plumbing disinfection) to minimize the risk of intestinal distress due to activated bacterial growth in the pipes.

Note on one thing plumber said - when flushing, you need to drain at ALL outlets so all pipe runs are flushed, not just outside ones.

One other thing that caught my eye - sounds like you are not sure your feed pipe from the street is plastic - I would find a way to check that out - at meter box maybe, where pipe comes into house, or if you are not in a real deep frost area dig down to it where it comes into the house. Could be galvanized or ductile, and at 36 years would certainly be a likely candidate for severe rusting occurring. If you have neighbors who have lived there foreever, see if they remember your lines being replaced - and if they remember for sure what type was put in. Don't trust their memory too much, but might be a help. Also call your water utility and see if their records show what type of pipe was connected to their system - they might have noted it on their plans.

Answered 5 years ago by LCD


Flushing the lines is a good idea but it should only take just a few minutes not hours. Begin with the outside faucets then the interior ones. As for the rust. Iron in the water can stain PVC pipes a reddish brown color but it should not leave deposits. As for the source of this the first thing I would check is the water heater. It will have a steel tank which collects alot of sediment. It is recommended to be drained and flushed at least once per year. If thats not your culprit I would have a plumber check to see if the hydropneumatic or pressure tank on the well has been disconnected from your plumbing. It should have been disconnected when you went to city water but its possible that it was not and years of buildup in this tank could cause this.

Answered 5 years ago by JCody


metal and rust will not stick to pvc. if you have that its coming from somewhere else , but not your pvc pipes, flushing the lines sounds fine, but where in the line is the rust coming from? thats sounds like heater tank problems, do you get the rust in cold water only? if not or at a much lower rate then its something in the hot water line.

Answered 5 years ago by the new window man


Re the comment by NewWindowMan - he is right that sediment and rust generally does not stick well in plastic piping - BUT:

1) if it is moving through the pipes from some other source, it will accumulate at the bottom of the pipe in slow-moving water areas, and at the bottom of vertical pipe runs, so can be flushed on through during high flow usage.

2) if you are forming algae or iron/lime deposits in the lines (albeit those more commonly occur in metal piping), they can form up and create a solid mass in the pipe regardless of pipe type. Then break free and migrate through the piping under high flows - the breakup can be due to water chemistry or significant temperature changes, higher chlorination level, or the pipes being bumped by stuff being moved around hitting them, the pipes being worked on, or earthquske or such.

Answered 3 years ago by LCD

Related Questions

Terms Of Use
Privacy Policy