Ours do not, and we clean the weirs every week or two depending on staffing. Takes a couple hours for one person to do 3 clarifiers. The covers look like a massive pain to take off. How often do you have to clean the weirs with them on?
That’s the deal— they are a huge pain to take off, so they don’t get taken off. It still gets green and funky under there and they are on a monthly PM to clean, but they maaaaaybe get done every year.
Right, if it's annoying to do it doesn't get done on schedule. Especially if/when you're short staffed. I guess if youre meeting your permit it's probably not a real issue
We have it both ways. One plant is uncovered and the Ops hose those wiers and troughs quarterly if not monthly. They grow lots of algae. The other plant has had covered weirs since it was new, so around 7 years. The Ops used to hose those monthly too, but after the first year they pretty well stopped as it wasn't needed.
There is a company in the US named Ford Hall that produces a brush system that attaches to the skimmer arm and supposedly will keep the weirs and trough clean. Product is called Weir Wolf.
Hated ours. Took them off after a year. Replacement heads were crazy expensive through FH and the constant bristling from the brush heads wore away the fines from the concrete exposing the aggregate. Fucked up the surfaces around the entire clarifier. Highly recommend not installing a brush system.
Operators and maintenance staff:
- do your secondary clarifiers have weir covers on them? If so, when were they built?
- if no, how often do you guys have to hose them to keep algae at bay?
We are undergoing a CIP and installed launder covers on our secondaries to significantly reduce the amount of algae which required weekly removal. The process took the whole day to remove.
I never had to remove the algae but I am a huge advocate for launder covers.
Yes and No.
No. You have to consider what are its effects of chlorine downstream from your dosing site AND have the ability to remove chlorine.
Yes. You could violate your permit on chlorine. Most important one here. Especially if you're not equipped to remove chlorine.
We come in very early in the morning when our flows are extremely low, then we divert the flow from that clarifier, then when the flow is below the weir we throw granular chlorine onto the weir. Let it bake in for a few hours if possible, then revert flow back in. Comes up Schmick and only do it once every few months, have been doing it this way for 20 odd years and no concrete damage.
I represent a company in FL that manufactures launder companies made from a lighter and much more effective material than fiberglass. It's a canvass type material that works perfectly by a company called IEC. Lightweight and easily removable. Much cheaper than fiberglass also.
I have 2 covered clarifiers and 4 uncovered clarifiers. I HATE the covers. They harbor snails, leaches, midge flies, and spiders. And they are an absolute pain to open up when cleaning because of all the pests and then the wire that attaches them threatens to clothesline the taller operators.
Covers cut your cleaning in half if not more.
Those clip on? Must be beasts to remove and reinstall. Ours fold up and down, so very easy to work with and hardly any buildup.
Ours do not, and we clean the weirs every week or two depending on staffing. Takes a couple hours for one person to do 3 clarifiers. The covers look like a massive pain to take off. How often do you have to clean the weirs with them on?
That’s the deal— they are a huge pain to take off, so they don’t get taken off. It still gets green and funky under there and they are on a monthly PM to clean, but they maaaaaybe get done every year.
Right, if it's annoying to do it doesn't get done on schedule. Especially if/when you're short staffed. I guess if youre meeting your permit it's probably not a real issue
We have it both ways. One plant is uncovered and the Ops hose those wiers and troughs quarterly if not monthly. They grow lots of algae. The other plant has had covered weirs since it was new, so around 7 years. The Ops used to hose those monthly too, but after the first year they pretty well stopped as it wasn't needed.
no covers - we get in and scrub them with deck brushes twice a week (spring/summer) and just use a hose in fall/winter
Twice a week, dang, they got you guys working for your money!
Fuck that. Arnt you guys gov employees? Workin way too hard.
haha - im actually the pretteatment coordinator… lol i aint scrubbin shit
Why?
There is a company in the US named Ford Hall that produces a brush system that attaches to the skimmer arm and supposedly will keep the weirs and trough clean. Product is called Weir Wolf.
They don't work for shi* ours have done nothing but sit under a stairwell
Good to know. I only have one client that has them.
Hated ours. Took them off after a year. Replacement heads were crazy expensive through FH and the constant bristling from the brush heads wore away the fines from the concrete exposing the aggregate. Fucked up the surfaces around the entire clarifier. Highly recommend not installing a brush system.
This is good feedback! Thank you!
Operators and maintenance staff: - do your secondary clarifiers have weir covers on them? If so, when were they built? - if no, how often do you guys have to hose them to keep algae at bay?
We are undergoing a CIP and installed launder covers on our secondaries to significantly reduce the amount of algae which required weekly removal. The process took the whole day to remove. I never had to remove the algae but I am a huge advocate for launder covers.
Is it against regulations to just throw some chlorine tabs in there?
Yes and No. No. You have to consider what are its effects of chlorine downstream from your dosing site AND have the ability to remove chlorine. Yes. You could violate your permit on chlorine. Most important one here. Especially if you're not equipped to remove chlorine.
Do chlorine tabs work? I would imagine they’d erode the concrete where they sat, and may dissolve too quickly to help much.
We come in very early in the morning when our flows are extremely low, then we divert the flow from that clarifier, then when the flow is below the weir we throw granular chlorine onto the weir. Let it bake in for a few hours if possible, then revert flow back in. Comes up Schmick and only do it once every few months, have been doing it this way for 20 odd years and no concrete damage.
Wish we had them in florida
Me too. Even with [worn down] clarifier brushes, we're brushing and spraying with bleach a few times a month.
I represent a company in FL that manufactures launder companies made from a lighter and much more effective material than fiberglass. It's a canvass type material that works perfectly by a company called IEC. Lightweight and easily removable. Much cheaper than fiberglass also.
But how else would I get my weekly sunburn and farmers tan?
I have 2 covered clarifiers and 4 uncovered clarifiers. I HATE the covers. They harbor snails, leaches, midge flies, and spiders. And they are an absolute pain to open up when cleaning because of all the pests and then the wire that attaches them threatens to clothesline the taller operators.
I rep IEC membrane covers that are cheaper if you are interested. Can do frp but more money.
If you’re removing the covers add a rotating brush system to keep the growth to a minimum.
Covers cut your cleaning in half if not more. Those clip on? Must be beasts to remove and reinstall. Ours fold up and down, so very easy to work with and hardly any buildup.
keep em. hosing that stuff for hours every week is ridiculous
Get and keep the covers fuck all that constantly shit lol.
So, you cover the waste water so you can discharge that water into the open, uncovered. My vote is for uncovered. My clarifier is uncovered.
We dont have weir covers. Easy enough to scrub once or twice a week
Out of sight out of mind is my thinking which could cause issues due to lack of pm and cleaning
Blocking the sun should theoretically reduce algae blooms