Pumped waste solution for garden room?

[dilalio]

Have a customer who builds garden rooms for clients.

First one I went to, they had already done most of the plumbing install themselves.

Waste run to drain and macerator installed to supply wc, basin and shower.

Ended up with shower waste being level (if not slightly lower) than inlet to macerator, so tray filled slightly before macerator pumps water away... It was on the brink with clean water but could see it being an issue with soapy water and the eventual build up of sludge in the pipe!

Tray not able to be raised due to lower ceiling height at the rear of the construction.

They also ran the underground drain in 32mm waste pipe. Or maybe 40mm.

Moving on to the next one, they have a potential project where the drain is 40m away from the room and 3m higher!

Also, the ground where the construction is going, occasionally floods to a depth of a few centimeters as there is a failed land drain nearby.

I have been thinking about solutions...

A lifting station, outside the room, in the ground but would this be an issue with the land flooding?

A whale pump that could push waste from the tray into the macerator.

Or simply a tray with raised edges to deal with the slight back flow from tray to macerator.

Would be grateful for any input, suggestions etc.

@just pumps
@Hugh Jaleak
@HERTS P&D

Et al.

Cheers
D

 

[Hugh Jaleak]

First scenario, I wouldn't be happy leaving that with a client, especially for commercial use. Is there any option to get a better fall on the pipework?

Second site, given the building is for commercial use, and the associated loss of income etc should something go wrong, I personally wouldn't be putting my trust in a Macerator. If it packs up, then that's the Facilities out of order, and if that means they cannot operate/trade, then they're totally reliant on a third party to effect repairs and get things operational again.

I'd look at a small pump package, it would give the option for some degree of retention if the pump was to fail, fit a visible warning to indicate if levels have risen too far due to pump failure, and then gives opportunity in a worst case scenario, for a portable submersible to be used to empty the holding tank if a replacement pump couldn't be sorted in the short term.

Would need to be properly installed, (may need surrounding in concrete to prevent buoyancy when empty), and sealed to prevent ingress of groundwater.

 

[dilalio]

First scenario, I wouldn't be happy leaving that with a client, especially for commercial use. Is there any option to get a better fall on the pipework?

Second site, given the building is for commercial use, and the associated loss of income etc should something go wrong, I personally wouldn't be putting my trust in a Macerator. If it packs up, then that's the Facilities out of order, and if that means they cannot operate/trade, then they're totally reliant on a third party to effect repairs and get things operational again.

I'd look at a small pump package, it would give the option for some degree of retention if the pump was to fail, fit a visible warning to indicate if levels have risen too far due to pump failure, and then gives opportunity in a worst case scenario, for a portable submersible to be used to empty the holding tank if a replacement pump couldn't be sorted in the short term.

Would need to be properly installed, (may need surrounding in concrete to prevent buoyancy when empty), and sealed to prevent ingress of groundwater.

Cheers Hugh,

I've been in touch with this firm...

190S - Mini Sewage Pumping Station (190ltr) 6m Lift

The 190S sewage pumping station is a complete kit for use in areas where gravity flow is not available.This system is used for the transfer of sewage or waste water, all specially designed for easy installation. All our pumping stations comply to BS EN 12050-1:2001 / BS EN 752-6:1998 standards...

www.sumpsandpumpsdirect.co.uk

Looks a good solution.

The builds are not commercial... Well last wasn't.

I warned them about the issue on the last one and they understood... They'll sort it under warranty if it's an issue with the customer and it's down to them.

No way to get a better fall as level with macerator inlet... Have put a non return trap in to try and prevent backflow.

I've only been with them since finishing off the last one and hopefully will be working with them on future builds - hence why they're asking my advice going forwards.

Good advice about concreting the tank in to overcome buoyancy - thanks.

 

[Hugh Jaleak]

If you're putting your name to it, Mono may also be worth knowing, https://www.mono-pumps.com/ See a lot of their kit on our sites, and given the abuse the Public give the sewerage system on a daily basis, they cope well. Some site have to pump effluent several miles, to a point where Gravity can take over again.

NRV worries me, especially with little fall, but might keep you in work, looking after it!

Have seen fibreglass septic tanks 'pop up', back out the ground after being emptied, when the water table has been high. Many manufacturers now insist their products are refilled with water immediately after emptying to equalise the pressure inside the vessel.

 

[just pumps]

First case. In time the macerator will become slower to activate due to internal parts becoming dirty or worn so a strict service interval will need to be stuck to. If the pipe from macerator to drain is underground then 32 or 40mm pipe with a fall this is correct (No rise alowed at all).

Second case. For me I would install a lifting station buried outsde in the ground. One with 2 pumps that activate in turn so not leaving one on standby ready for use for long peroids of time with a contol panel showing which pump is running, manual On/Off controls and a high water level alarm light. These are easy to "Service" with a washing up brush fixed to a broom handle and a garden hose to wash down.

Been 15yrs or more since I saw and heard a Mono pump working but back then they were noisy and enclosed in a pump room.

 

[dilalio]

If the pipe from macerator to drain is underground then 32 or 40mm pipe with a fall this is correct (No rise alowed at all).

Yeah, don't think it will have a fall.
So needs smaller bore to allow pump to push through?

 

[dilalio]

Second case. For me I would install a lifting station buried outsde in the ground. One with 2 pumps that activate in turn so not leaving one on standby ready for use for long peroids of time with a contol panel showing which pump is running, manual On/Off controls and a high water level alarm light. These are easy to "Service" with a washing up brush fixed to a broom handle and a garden hose to wash down

Have a model you can suggest?

 

[just pumps]

Yeah, don't think it will have a fall.
So needs smaller bore to allow pump to push through?

Afraid not, most if not all macerators in a box give you low pressure in a pipe after a few metres so without a fall in the pipe you are pumping new water against old water which whilst will work it will kill the life span of the pump/motor. The lifting stations have a very different type of pump hence they can move waste over a greater distance.

Because you were called in after the plumbing was started by the builder I fear it may be a mission impossible. You could try talking to Pump Technology in Berkshire about both your cases and see what they say as they know their stuff but also know how to charge so be sitting down.

 

[HERTS P&D]

The pumping station is the way to go, get it fitted then it is up to the customer to have it serviced and repaired when needed.

Andy