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loreen130319 May 2016 21:46Hello everyone,
We are close to submitting our building permit / planning permission, and our builder claims that we are required to plan and install a backflow prevention system.
We understand this in principle. However, what really isn’t clear to us is why we are not allowed to install a backwater valve for sewage and are allegedly required to install a lifting station (sump pump system).
Here is the situation:
The plot is completely flat, and rainwater is not allowed to be discharged into the sewer system anywhere in the development; it must drain into an infiltration pit. Our ground floor is located approximately 30cm (12 inches) below the last backflow level in the sewer. The property / development is situated on top of a hill, so no water is flowing downhill toward it; in fact, water drains away quickly.
This means that for a rare event that might occur once every five years, when the sewer cannot handle the rainwater, we are supposed to install a lifting station.
In our opinion, a backwater valve would clearly be sufficient in this case, not a lifting station. The lifting station serves a different purpose for us. Furthermore, this system is not allowed to be installed outside the building, so we would have to have a flap and the system under the slab in the utility room.
The whole setup is estimated to cost about 7,000 euros (around $7,700) without any excavation work.
Are we being too simplistic, or is the builder correct?
By the way, for insurance purposes, a backflow prevention device is important. A flap valve alone should be enough and certainly achieve the same effect.
Thank you for your opinions.
We are close to submitting our building permit / planning permission, and our builder claims that we are required to plan and install a backflow prevention system.
We understand this in principle. However, what really isn’t clear to us is why we are not allowed to install a backwater valve for sewage and are allegedly required to install a lifting station (sump pump system).
Here is the situation:
The plot is completely flat, and rainwater is not allowed to be discharged into the sewer system anywhere in the development; it must drain into an infiltration pit. Our ground floor is located approximately 30cm (12 inches) below the last backflow level in the sewer. The property / development is situated on top of a hill, so no water is flowing downhill toward it; in fact, water drains away quickly.
This means that for a rare event that might occur once every five years, when the sewer cannot handle the rainwater, we are supposed to install a lifting station.
In our opinion, a backwater valve would clearly be sufficient in this case, not a lifting station. The lifting station serves a different purpose for us. Furthermore, this system is not allowed to be installed outside the building, so we would have to have a flap and the system under the slab in the utility room.
The whole setup is estimated to cost about 7,000 euros (around $7,700) without any excavation work.
Are we being too simplistic, or is the builder correct?
By the way, for insurance purposes, a backflow prevention device is important. A flap valve alone should be enough and certainly achieve the same effect.
Thank you for your opinions.
I think you might be mixing things up. The lifting station (sewage pump system) is for wastewater, not rainwater. The rainwater should be discharged on your own property.
The lifting station raises the wastewater so that it can flow from your lower house to the higher street level. Since the street is only about 30cm (12 inches) higher, the height difference should actually be sufficient. If not, please explain more precisely what you need.
Rainwater pipes for on-site infiltration are NOT connected to the public sewer system. A lifting station does not make sense here, unless the house is significantly lower than the rest of the property. Even in that case, it would probably be more economical to simply dig deeper for infiltration.
The lifting station raises the wastewater so that it can flow from your lower house to the higher street level. Since the street is only about 30cm (12 inches) higher, the height difference should actually be sufficient. If not, please explain more precisely what you need.
Rainwater pipes for on-site infiltration are NOT connected to the public sewer system. A lifting station does not make sense here, unless the house is significantly lower than the rest of the property. Even in that case, it would probably be more economical to simply dig deeper for infiltration.
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Polle 196720 May 2016 09:43What about a basement? If you have one and there is wastewater present, then the lifting station is exactly designed for this purpose.
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loreen130320 May 2016 11:23This is solely about the case where the sewer cannot handle an excessive amount of rain. Only if that happens does the system activate.
The house is on flat terrain, slightly above street level, which is evened out by paving or a step at the front door. The final backwater level in the sewer (quite a bit further down the street) is about 30cm (12 inches) below our ground floor. Neither the street nor the house has been built yet. However, these are the planning data currently available.
The house is on flat terrain, slightly above street level, which is evened out by paving or a step at the front door. The final backwater level in the sewer (quite a bit further down the street) is about 30cm (12 inches) below our ground floor. Neither the street nor the house has been built yet. However, these are the planning data currently available.
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loreen130320 May 2016 11:24We are building without a basement
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