Distance between sewerage wells and other standard

The purpose of writing this article is to put together the basic requirements for dimensions and distances, which should be followed when laying the drainage system. We have to find out what the minimum distance between the sewer manholes can be, what is the size of the protection zone of the treatment plant and what the diameter of the sewer pipes can be. So go.

Information sources

The main source of information for us will be the USSR State Committee for Construction, SNiP 2.04.03-85, adopted in 1986. It regulates the laying of external sewer networks and the construction of related structures.

It is curious: almost simultaneously with it, SNiP 3.05.04-85 was adopted, describing the requirements for the construction of external water supply and sewerage networks. If the first document is devoted mainly to the design of waste systems, the second focuses on the materials used and the installation technology.

We will have to gather some information in another document - the code of rules SP 32.13330.2012. This is an updated version of SNiP 2.04.03-85, approved in 2013, which does not cancel its effect, but introduces some additions to the text.

Wells

Let's start with the requirements for the location of wells. To do this, we will have to start by examining their types.

Types and purpose

• Inspection wells serve to control the work of the sewage system and, most importantly, to clean it in case of unavoidable blockages.
• Rotary - perform the same function at the points of change of direction of movement of stocks. Any pipe bend is always a place of increased risk; access to it completely solves this problem, allowing you to clear the clog when it occurs.

• Differential slope compensation. Excessive bias is no less harmful to the work of the waste system than its absence: excessively rapid movement of the effluent leads to the fact that solid fractions accumulate in the pipe, gradually reducing its clearance.
• Hubs are equipped at the joints of pipelines.

Location

The smallest distance between sewer manholes according to SNiP for manholes is determined by the size of the pipe connecting them.

Nodal wells, as it is easy to guess, are equipped in all places joining sewer lines; rotary - where the pipe changes direction. In addition, they should be provided for in the project at the points of change of the slope or section.

Dimensions

The section of the round well is again determined by the section of the pipe:

• Up to 600 mm - 1 m;
• 700 mm - 1.25 m;
• 800 - 1000 mm - 1.5 m;
• 1200 mm - 2 m.

However: with a depth of more than 3 m, the smallest diameter is 1.5 m.

The height of the working part of the well (from the tray or shelf to the lid) is usually taken equal to 1800 mm. It is clear that the instruction is not always applicable: the terrain can force to increase or decrease the depth. If it is 1.2 meters or less, the cross section increases with respect to the above values ​​by 300 mm; while it should not be less than a meter.

Throats are not made 700 mm; when using large pipes, they should skip cleaning tools.

Pipes

When laying the drainage system should be based on the following smallest values ​​of pipe sizes:

In addition, the SNiP regulates pipe slope.

It is relevant not only for external networks: these same values ​​should be followed when laying internal sewers with their hands.

• For 50 mm pipes, the optimal slope is 0.035 (3.5 cm per linear meter).
• For 110 - 0.02.
• 150-0.01.
• 200 - 0.008.

Sanitary protection zones

Their size is determined by both the type of structure and its performance.

What should be the distance from the sewer to the basement of the cottage?

Here are the parameters that should be followed when designing an autonomous sewage system for a private house (capacity - less than 15 cubic meters per day).

• The sanitary protection zone of the underground filtration field is 15 meters.
• For a filter trench or sand and gravel filter, it is 25 m.
• A septic tank can be built 5 meters from the foundation, and a filter well can be built at 8.

Turns, depth

What is the smallest turning radius of a collector pipe?

1. With its cross section up to 1200 mm, it is equal to the diameter of the pipe.
2. If the pipe is thicker than 1200 mm, the minimum turning radius is equal to its five diameters.

Important: in the latter case, inspection wells should be constructed at the beginning and at the end of the turning curve.

What is the minimum depth you can lay sewer?

The value is determined primarily by the depth of soil freezing and the experience of operating sewer networks in the region.

If there is no operating data, the minimum depth of the sewer pipe is:

• With a cross section of up to 500 mm - 0.3 m above the depth of soil freezing;
• With a larger cross section - 0.5 m above the level of freezing.

In both cases, the distance from the top of the pipe to the ground surface or a zero level mark cannot be less than 0.7 m. The price of breaking this rule is an increased probability of pipes freezing at the peak of frost and damage by passing vehicles. If, for some reason, the condition is impracticable, the pipes are laid in a concrete tray and additionally insulated.

Conclusion

We hope that the materials offered to the reader will help him in the design and self-construction. As usual, the video in this article contains additional thematic information. Successes!