Why do we need a sump pump?

Gravity makes fluid flow downwards. Stormwater (rain water) and Sanitary (sewage) connections are provided by the municipality. Normally the municipal mains (storm and sanitary conencitons) are well below in the street and hence well below the minimum basement elevations (MBE). So one can drain the perimweter drain (storm water) and sanitary from the from the lowest level by gravity. All you need is a big enough pipe (calculated) and a slope (drop towards the flow) and the effluents drain by gravity. Quite simple as long as the pipes are sized and sloped properly. Building codes dictate the sizing of the drains.

There are areas where the municipal mains are higher and the lowest plumbing fixtures and/or perimeter drain or lawn basins of the property cannot be connected to the city mains. In such cases, we have to mechanically lift the effluents (storm and sanitary water) to a level from where they can be connected to the city mains by gravity. This is done by sump pump system.

Not as common – but there are times when even the municipality is pumping the storm or sanitary to a higher level. In this case, one must have a sump pump strong enough to pump against the pressure in this pressurized main pipe. We need to get the information of the instaleld system from the municipaity before the pumps can be sized.

Basically a sump pump is a water lifting deivce used to remove water/sewage that has accumulated in a basin. 

Sanitary Sump Pump

Sanitary sump pump is used to pump the raw sewage of the entire house or building or for just the levels which cannot be drained by gravity. Typically, it is just the basement which requires pumping.

There are two types of sanitary sump pumps:

1. Non-clog type pumps are used for systems where the pump drains to gravity city mains, travel distance for pumped effluents is not too long and not much head is required. Basically the pump lifts the effluent to a level from where gravity takes on. 
2. Grinder type sump pumps are used when the sump pump needs to pump the sewage at longer distances and high heads. The idea is to grind any solids so that it can be easily pumped. This is also used for the systems where the effluent needs to be pumped into a pressurized system which itself is being pumped to a higher level. 

The sanitary sump pumps are required to pass stack tests to ensure they don’t leak in the event of failure. The stack test varies from 5 feet to 15 feet, depending upon the city.
The sanitary sump pumps can be placed inside the house or outside. Important thing to note is they must be placed at the basement level. Inside the house, these are placed in the mechanical rooms and outside they are usually in the patio.
Indoor pumps can be any of the following:

• Engineered Pump Systems

  Engineered Pump Systems is a Coquitlam, BC Canada based sump system supplier. They provide engineered packages of the sump, pump, floats and controls. They stack test them in their shop and deliver on site. They use Zoeller and Meyer Pumps. Engineered Pumps sells the sump pumps directly to the clients.

• Liberty Pumps

  Liberty Pumps have pre-engineered and stack tested models along with non-stack tested models. For sanitary the indoor sump pumps must be able to withhold a stack test of 10 feet. Either the sump assembly comes pre-tested or the test be performed on site with the engineer and inspector witnessing it. Point to remember is not all the Liberty pumps are stack tested. Taking them out and replacing them with the right one is very disruptive. Liberty Pumps are sold by distributors in the lower mainland, but represented by Concur West.

• Meyers

  Meyers do not have a full system, but the pumps can be used in other sump systems.

• Zoeller
  

  Zoeller Pumps do not have a full sump system, but the pumps are used in other sump systems.

• Saniflo
  

  Saniflo Pumps has a packaged system as well. We have not used it – so I cannot comment more.

STORM SUMP PUMP

Storm sump pump is used for the rain water which cannot be drained by gravity. Typically, it is the perimeter drain (also called footing drain). And at times the lot’s lawn basins and rain water leaders are also drained to a sump and then pumped to the city mains. The water volumes are calculated based on the rainfall data from the building codes and geothechnical reports for perimeter drains. The sump size and the pumps are selected to allow for adequate pumping of water. Bascially we want to pump faster than the sump/basin filling up. 

Do I really need two pumps?

A Simplex or Duplex System depends on the type of installation and/or local codes. Generally, the storm sumps aer requried to be double as the municipality wants to ensure the system has maximum runtime as your perimeter drain or storm water can affect other properties around. Some jurisdictions call for a generator back-up as well. For sanitary a single pump is acceptable and adequate to do the job. BUT we always recommend two pumps. If one pump fails, the second redundant pump will do the job AND the alarm panel will provide some annunciation (alarm). You have some time to change the pump. With a single pump, you literally have to stop using your washrooms or any other fixtures which feed this sump.  

What information must I provide the Engineer?

While we are sizing the system and before  we can select a pump, we will need the following information: 

1. Your house drawings from your designer (or architect).

2. Your lot drainage plan from your civil engineer

3. Voltage available

4. Preferred locaiton of the sumps.

Piping Material

• The internal piping in the sump itself is usually PVC schedule 40 with schedule 80 fittings.
• The forced mains can be PVC schedule 40, but we call for schedule 80 as these pipes are buried about 18”-24” deep and can be subject to higher pressures inside the pipes and to some extent load from above.
• Flex pipes might be rated for the pressure and usage, but the fittings are not rated for sewage or storm water. So Flex pipes are not allowed by code.
• The rain water leaders are always solid PVC pipes.
• The perimeter drain is perforated PVC pipe. The old “Big O” pipes are not permitted.
• Use of 90 degree elbows is not permitted for sanitary. Use of two 45s is required at any bends.