Design of sewerage and wastewater systems. SNIp for sewerage systems Pressure sewer design standards

External sewer networks, according to SNiP, are used both in private country houses and in city apartments. This sewage system is very convenient, easy to use and environmentally friendly. To install it, you must familiarize yourself with the rules of use according to SNiP

Features and types of sewerage systems SNiP

These sewerage networks are a branched pipeline that delivers wastewater from premises (residential and non-residential) to special containers. To ensure that wastewater flows into the tank by gravity, water pipes are installed at a slight slope.

Second version of the system provides for the installation of pressure networks or connecting a special pump.

Types of sewerage systems according to SNiP

Depending on their purpose, sewer networks are divided:

Household, which is divided into two types: central (serving the entire village) and autonomous (for one or more houses).
Industrial(industrial treatment facilities).
Stormwater providing drainage after rain.

All of these types are divided into two subspecies:

Outdoor (pipes are located on the street, including treatment plants and structures).
Internal (everything that is located indoors).

According to the method of installation and laying of the SNiP pipeline, external communications are divided into several types:

In addition, sewer networks differ in other ways.

SNiP external sewerage systems

External communications can be located in different places and vary in purpose. There are several types of outdoor sewerage networks:

Methods for laying water pipes are determined individually in each specific case. This depends on several factors, such as bends and turns along the route, the level of groundwater, etc. It should be remembered that sewer pipes are in any case laid with a slope, which varies depending on the diameter of the pipe. In some cases, it may be necessary to install a pump, drainage or inspection well.

Components of an external sewerage system

The sewerage network consists of various elements that allow the transport of wastewater to treatment facilities. In general, the sewerage system includes the following parts:

In addition, for the full operation of the sewerage system, it is possible to use other additional elements.

Material for the manufacture of sewer pipes

The service life of the pipeline also depends on the choice of material. Today, the rules provide for the use of materials such as:

In rare cases, it is possible to use glass or ceramic pipes.

Since wastewater with all sewage immediately flows from the internal sewerage system to the external one, the latter must cope with a huge volume of sewage at the same time.

Installation of an external sewerage system

To ensure the reliability and long service life of the sewer system, a number of rules must be followed during its installation.

SNiP requirements are based on factors such as:

soil properties;
climate features;
ground water level;
average wastewater volume;
distance to the nearest pumps and treatment plants.

It is also very important to maintain the level of inclination of the pipe to ensure the unhindered passage of wastewater by gravity. According to the requirements of SNiP, t rubles must be laid at a certain slope to the side of the well. The angle of inclination is determined by the diameter of the pipe and is 2–3 cm per meter of pipeline.

Do not try to make a large slope: this, of course, will facilitate the rapid drainage of a huge amount of waste, but can lead to clogging of the system, since solid particles will be retained in the pipe.

According to the requirements of SNiP, the size of the pipe for the external sewerage of several houses included in the system must be at least 20 cm, and for one country cottage - 10–11 cm. When planning the installation of a sewage system, additional factors that affect performance in the future should be taken into account .

Before proceeding directly to the installation of the sewerage system, it is necessary to carry out preparatory work: study the soil features, calculate all elements, lay out the route of the pipeline.

The first step is to determine the location of the collection well where the wastewater will flow. In this case, the type of water collector is also taken into account: a septic tank, which is capable of not only receiving, but also disposing of pollution, or an ordinary well.

The ideal location for a septic tank or well would be the lowest location in the pipeline area. If you plan to clean the collection using a sewer truck, it is better to locate the well closer to the roadway for its comfortable maintenance.

A trench is dug, which, if necessary, is supplied with additional parts. Carefully secure the pipe joints and treat them with sealant. To prevent water pipes from freezing in winter, it is necessary to carry out thermal insulation. The sewer system is then connected to a treatment plant or sewer and a test run is performed.

The ditch is filled and compacted only after a complete check of the entire structure as a whole.

Requirements for pipeline parts:

Resistance of the material to corrosion or providing additional protection.
Availability of a base for pipeline installation, taking into account soil characteristics.
Mandatory use of valves, plungers and other additional elements in pressure sewer networks.
Installation of inspection wells only in places of slopes, intersections and bends of the water supply system. The size of the well is determined by the diameter of the pipe and its length. Wells must have sewer hatches, ladders and fences.
Rainwater receivers should be installed near pedestrian crossings, low-lying areas and places where large numbers of people gather.

SNiP requirements for sewerage of a private house

Sewage in apartment buildings is taken for granted and is almost invisible. Another thing is the disposal of wastewater in a private house. Cesspools and street toilets are considered a relic of the past, and many owners of country cottages are thinking about construction of a sewerage system on your site. In order to independently install and connect a waste pipeline, you need to know the building codes and regulations, compliance with which will ensure long and uninterrupted operation of the system.

Sewerage is installed immediately during the construction of a new house, but it is quite possible to equip an old one with an outdoor toilet with apartment amenities.

Private houses are divided into two types: those with the ability to connect to the central sewer system and those that cannot be connected.

The procedure for carrying out intra-house installation work will be the same, the only difference is in the removal of wastewater from the premises.

The sewage system of a private house, as well as an apartment building, consists of sewer pipes and risers connected to each other. Wastewater from toilets, bathtubs and sinks enters horizontal pipes and goes through a riser to a treatment plant or sewer system. If you are just planning to build a house, it is necessary to locate the kitchen and bathroom next to the place where the sewer pipe exits the house. If the cottage is multi-story, then for ease of installation of the pipeline, the bathrooms must be located one above the other.

Pipe installation and plumbing installation

The toilet is connected to the vertical riser separately. To prevent waste from entering the pipes, the remaining elements must be located above the toilet.

To reduce noise levels, the risers can be closed in a plasterboard box or wrapped in mineral wool. All necessary parts are attached to the pipes using elbow siphons, in which there is always a small amount of water, which blocks unpleasant odors from the system and prevents them from escaping outside.

Horizontal pipes that are located under the floor, in the basement or basement, are connected to a riser with external pipes. Elements located outside the premises should be x insulate well to prevent them from freezing during the cold period. At the exit from the house, all pipes are collected into one and connected to the external sewage system. Clamps are used as fastening.

In order to prevent the appearance of specific odors when draining water, ventilation should be installed: a vertical riser is led up to the roof, and its upper part must be well strengthened, not covered, but only protected from debris and precipitation. You can also install an aeration valve to keep out odors.

A trench is prepared, the depth of which is determined by the level of soil freezing in a particular region. To the bottom of the ditch is a must sand cushion is laid, on which drainpipes are mounted at a slight slope. If, due to the characteristics of the soil, it is impossible to dig a deep trench, the pipeline should be carefully insulated.

Private houses generally have an autonomous sewer system, which comes in 4 types:

Dry toilet. Convenient, but requiring constant costs, type of sewerage.
Cesspool. Cheap, but very inconvenient to use.
Septic tank. It is capable of not only receiving wastewater, but also purifying it independently.
Treatment facility. Cleaning is done using special bacteria. Quite effective, but at the same time - an expensive type of sewer system.

Each of these options has its pros and cons. For example, it is better to install a cesspool in areas that are used periodically.

The cleaning station does not require constant maintenance, but its disadvantage is its high cost. Of the proposed sewerage options for a private home, the ideal would be a septic tank, which you can assemble yourself or buy ready-made.

So, by observing the rules of SNiP external sewer networks, and following the proposed recommendations, you can easily install a sewer system at home and thereby ensure comfortable living for yourself and your loved ones.

The construction of buildings used by public catering establishments - or - cannot be completed without competent sewerage design. The storm sewer network system, found in almost every home, requires drainage from the canopies and roof.

Sewerage design is extremely important for installers due to the fact that the project allows you to foresee problems that are not visible at first glance and avoid them. Sewer pipes, as a rule, are gravity-fed, unlike water supply pipes, in which water is under pressure, and they themselves can be laid in walls, in the floor, and under the ceiling at almost any angle. Laying sewer pipes is possible only with strict compliance. The size of the floor screed directly depends on the slope. Sewer risers need. Connecting plumbing fixtures located in the basement is necessary only through a check valve with an electric valve; otherwise, the result as shown in the diagram is possible.

Sewer design is necessary for many reasons. First of all, it is worth noting that the sewerage project contains detailed specifications of all equipment and materials used in installing the system. And although sewer pipes are not the most expensive material, your unnecessary expenses on purchasing surplus will only be pleasant to the seller of these pipes. Designing a sewerage system will allow you to avoid such problems and offer optimal solutions for installation.

Sewage system plan

In addition, the sewerage project for new construction or major repairs with changes in the volumes of water disposal and water consumption is requested by supervisory authorities. When redeveloping, a water supply and sewerage project, along with others, is also necessary and is submitted to the housing inspection for approval. In most cases, the operating organization will not issue a permit for construction work without a sewerage design. Of course, it is possible to install sewerage and water supply without a project, however, no one can guarantee that after a while you will not encounter a number of problems (an unpleasant odor from pipes, blockages, etc.). When designing a sewerage system, many subtleties and nuances should be taken into account. First of all, it is necessary to comply with the relevant rules and regulations. For the design of internal systems of household, industrial and storm sewerage, they are registered in, for external - in. The accuracy and correctness of the drawings are regulated by and.

In order to take into account all the wishes and requirements of the customer, careful collection of initial data is necessary. First of all, the source of water supply and the volume of water consumption are determined - the number of people living in the house, the presence of additional equipment that requires a water supply connection. Central city networks or an autonomous well can be used as a source of water supply. To draw up a water supply and sewerage project, it is necessary to determine the point of sewage discharge and the layout of premises with plumbing equipment, appliances and other sources and consumers of wastewater marked on them. After collecting the necessary information, sewerage routes are drawn on the plans and approval takes place with the customer. At the design stage, it is necessary to provide thresholds and false walls in order to hide sewer pipes whose diameter exceeds that of the water supply pipes. The most ideal solution from the design side is, of course, laying pipes in grooves, however, this is only feasible if the supporting structures are not affected.

Pressure sewer design

The design of a pressure sewer system is justified in the case where the central sewer system is located close to the facility, but the terrain does not allow for the movement of wastewater by gravity. This option does not require the installation of treatment facilities and allows the use of smaller diameter pipes. When designing a pressure sewer system, a pumping station, one of the main elements of the system, is selected.

Design of external sewerage networks

External sewerage networks deserve special attention. To draw up technical specifications for the design of external sewerage, a general plan is necessary,

Storm drainage scheme

technical conditions for connections, topographic survey and geological research. Our company’s engineers draw up this technical specification together with customers. In addition, it can be compiled using, which is available for download, or on our website. After drawing up the assignment and signing the corresponding agreement, the direct design of external sewerage networks begins.

A VC project, as a rule, has the following composition:

Title page
General information about the project
Composition of the water supply and sewerage project
Balance of water consumption and wastewater disposal
Explanatory note
Floor plans with sewerage networks, industrial sewerage, storm sewerage,
Floor plans with hot and cold water networks
Axonometric diagram of sewerage, industrial sewerage, storm drainage
Axonometric diagram of cold and hot water supply
Units and parts of water supply and sewerage systems (if necessary)
Water metering unit diagram
Sewage system specifications

Design costs and timing are just as important as the high quality of projects. The average design time for water supply and sewerage for a small facility, if initial data is available, is 1 – 2 weeks. However, there may be cases when design needs to be completed within an extremely short time frame. You can find a complete list of prices for all projects on our website (see In addition, in the section you will find, which is available for download.

The Stroymetmashservice company provides services for the design and construction of external sewerage networks in the Moscow region and regions of Russia.

The scope of activity of SMMS for the installation of external sewerage networks includes the following types of work:

laying drainage pipes on sludge beds;
installation of a filter base for sludge beds and filtration moths;
installation and dismantling of shut-off valves and sewerage network equipment;
laying sewer pressure pipelines;
laying of non-pressure sewer pipelines;
installation of sewer and drainage wells;
installation of sewage pumping stations;
cavity cleaning and testing of sewerage pipelines.

These and other types of work performed are carried out in compliance with existing standards and safety precautions. Construction of sewerage networks within the time limits specified by the customer is the key to timely delivery of the facility.

The full range of services from SMMS includes:

design of external sewerage networks;
complete set of materials and equipment;
installation of elements of external networks and water supply and sewerage structures;
commissioning, system testing;
commissioning of the facility;
reconstruction;
warranty and post-warranty service.

Laying external sewerage networks from design to installation

The construction and laying of external sewerage networks is carried out in compliance with the requirements of regulatory documents SNiP and VSN. In the construction of external networks and sewerage structures, plastic (HDPE), cast iron (VChShG), and asbestos-cement pipes are used. All types of services for the installation of external water supply and sewerage networks provided by SMMS have an SRO approval for the work.

Development of a project for external storm sewer networks (calculation of the estimated cost and design of external sewer networks, obtaining technical specifications, approval of the project), registration of a positive conclusion of the state examination, development and approval of a work project (PPR), construction of sewerage engineering networks, installation of pipelines of external water supply networks and sewerage, repairs, warranty and post-warranty maintenance of facilities are carried out by qualified specialists of the Stroymetmashservice company at the best price. We provide the customer with timely progress reports. Transparency of the company's actions allows the client to make changes and adjustments if necessary.

To calculate the cost of work on installing external domestic sewage networks as a complex or as a separate service, contact the specialists of the SMMS company at any working time. We will be happy to answer your questions regarding the installation and maintenance of external water supply and sewerage networks, and the preparation of working drawings.

"Stroymetmashservice" - reliable quality at a decent price, professionalism and responsibility.

Rice. External engineering networks. Sewerage design.

A sewerage system is a complex of devices designed to drain various biological, chemical and household waste from human activity, as well as rainwater. Proper sewer design makes it possible to completely remove all solids and liquids by discharging them into the main drain with the flow of water.

Designing a sewerage system involves using one of two main types of pipeline.

Pressure pipeline. When designing a pressure sewer, the use of a pump or pumping station is provided. With the help of such equipment, a vacuum is formed in the system, transporting waste waste to the disposal area.
Gravity pipeline. The principle of operation of such equipment is to calculate the required angles of inclination of pipes at which waste spontaneously flows under its own weight to collection points.

When choosing a sewer type, you should consider:

Groundwater depth;
soil type;
requirements for the level of wastewater treatment;
prices for equipment and work.

Stages of designing a sewerage and wastewater system

Design of sewerage and wastewater networks includes the following stages.
Determining the type of sewerage. At this stage, they find out what type of sewage system is needed: autonomous, i.e. not interacting with the central highway, but discharging wastewater into the ground, or connected to the centralized network of a city or other populated area.
Determination of waste disposal method. At this stage, it is established what is more appropriate: designing treatment facilities or sewers with a dedicated storage area for wastewater. A septic tank, location and method of waste storage are also selected.
Determining the location of communication elements. When designing a storm sewer or any other type of wastewater drainage, the connection points of all elements, as well as the entry area into the central main line (if there is one), are determined.
Collection of initial data. At this stage, the following factors are studied:

topographical map of the area designed to establish connection points;
features of existing utilities;
conditions for using existing facilities;
customer requirements.

When designing an external sewer system, a set of devices is developed for collecting, transmitting, and treating wastewater of various origins and discharging treated wastewater to a water intake or to re-water supply elements. External sewerage is a significant element of the infrastructure of any building for the comfortable living of people in Moscow and the regions.
When designing water supply and sanitation, strict compliance with sanitary standards and rules is carried out. Only high-quality materials are allowed for consideration. Designing drainage requires calculating the cost of laying a pipeline made of polyethylene, polyvinyl chloride, and cast iron. To inspect and clean the network in case of blockages, inspection wells are provided, which are installed in all places where the diameter and angle of inclination of the pipes changes.

When designing cable ducts or other types of communications, the following are drawn up:

plan drawings;
axonometric diagrams;
specifications.

Documents required for designing rainwater drainage or other types of equipment:
1. technical specifications for sewerage construction;
2. topographic plan on a scale of 1:500 (geobase).

Correctly completed design and installation of external sewerage networks determines the duration and quality of their operation. The basic provisions and rules for the construction and repair of an external sewer network are determined by SNiP 2.04.03-85. The document regulates the full cycle of work on the installation of an engineering system, from pipeline installation to construction of treatment facilities. SNiP sewerage external networks and structures will help you select the optimal material and build an effective system for draining wastewater and rainwater.

What is external sewerage

External sewerage includes branched pipelines and system elements necessary for transporting wastewater from residential buildings and other facilities to treatment facilities. The design of the utility network is carried out simultaneously with the preparation of water supply plans. The systems are interconnected by the need to maintain a balance between water consumption and disposal. Installation and maintenance of urban external sewerage is the responsibility of public utilities. The maintenance of autonomous sewage systems in private houses is carried out by the owners themselves.

There are two ways to transport wastewater:

non-pressure or gravity;
pressure, requiring the installation of pumping equipment.

Types of sewerage

To ensure the safe operation of external sewage systems, SNiP offers several methods:

duplication of communications - providing the ability in case of an emergency to switch the flow to a parallel pipeline or channel;
reliable power supply, availability of an alternative (backup) source;
allowing for reserve when designing network capacity

Attention. When installing sewerage structures, a certain sanitary zone must be observed to the construction sites of residential and public buildings.

Structural diagrams

According to SNiP, external sewerage is divided into several systems according to the installation method:

All-alloy - according to this installation scheme, all wastewater - domestic, storm, melt - is directed into one sewer collector or container.
Separate - the system is designed so that household wastewater and melt (rain) water are transported through different pipelines and end up in various treatment facilities or storage tanks.
Semi-separate wastewater and storm sewer are sent through different mains into one container.

All-alloy scheme

Attention. It is prohibited to discharge wastewater into water bodies that has not been treated to established standards.

Classification of sewer system

External engineering communications are installed in various places and have their own purpose.

Yard network – used to serve one building. It consists of the following elements: small diameter pipes (150 mm), building outlets, intake and inspection wells. This concept is used for a system connected to a central sewer system; it is not used for an autonomous system.

Yard network

Intra-block network - the network is arranged inside the block, it consists of the same elements as the yard network.

The street network is designed to transport wastewater collected from all neighborhoods. Such a pipeline is called a collector; its function is to collect wastewater and discharge it to a pumping station or treatment plant.

Attention. Ground laying of sewer pipelines in populated areas is not permitted.

Schemes of drainage networks

Depending on the characteristics of the terrain, one of the external drainage schemes is selected:

perpendicular - used for rainwater sewer collectors to quickly transport water to the general flow;
zone - a rare option, applied to objects with a significant difference in height; a pump is installed in the lower collector;
cross-section - the main collector is installed along a river or other body of water to intercept wastewater;
radial - wastewater is directed to various treatment facilities.

Components of an external sewer system

The utility network consists of several main parts:

The choice of method for disposing of domestic and rainwater waste depends on a whole list of factors that are taken into account at the design stage:

properties and nature of the soil;
climatic features such as freezing depth;
volume of transported wastewater;
groundwater level;
distance from the point of release from the building to the treatment plant.

Attention. The lowest permissible pipeline slope depends on the minimum sewer flow rate.

Selection of material for the pipeline

The materials used for the installation of lines and channels must be resistant to aggressive environments and the effects of abrasive particles contained in the liquid. To prevent gas corrosion of the upper part of the collector, ventilation is installed to prevent gas stagnation.

SNiP for external sewerage provides for the use of pipe networks made from the following materials for installation:

polyethylene;
polyvinyl chloride;
polypropylene;
steel;
asbestos cement;
cast iron;
reinforced concrete.

Polymer pipes

Cast iron pipes

Reinforced concrete pipes

In rare cases, when installing a network, pipes made of ceramics and glass are used; such materials are allowed by the rules.

Polymer products are the best choice when installing external utility networks. They have all the qualities that ensure reliable and long-term operation of the system:

resistance to mechanical stress;
frost resistance;
high throughput due to smooth surface;
corrosion resistance;
durability.

Rules for installing sewer networks

Pipe diameter

The capacity of the free-flow network depends on the size of the pipes. Building codes determine the minimum diameter of pipes of a gravity engineering system:

street network – 200 mm;
autonomous sewerage – 110-150 mm;
intra-block – 150 mm;

The size of the rain and all-alloy street system is 250 mm, the intra-block system is 200 mm.

Speed

SNiP presents tables that determine the speed of movement of wastewater depending on the size of the pipeline or tray. These indicators help to avoid siltation of sewer networks. The flow contains suspended particles, which, if the speed is insufficient, settle on the surface of the line.

Basic calculation data:

diameter 150-250 mm – 0.7 m/s;
600-800 mm – 1 m/s;
more than 1500 mm – 1.5 m/s.

The lowest speed of movement of clarified waste through trays and pipes is 0.4 m/s. Maximum wastewater transportation speed:

through metal and plastic pipes – 8 m/s;
for concrete and reinforced concrete – 4 m/s.

For rainwater drainage, the indicators are:

metal and plastic pipes – 10 m/s;
concrete and reinforced concrete – 7 m/s.

Pipeline slope

One of the basic rules when laying a pipeline is compliance with the slope norm. For systems where the fluid moves under the influence of gravitational forces, this parameter is critical. The negative consequences of installation errors in the direction of decreasing or increasing the slope lead to improper functioning of the network, blockages and breakdowns.

Attention. The standard indicator is calculated per 1 linear meter of pipe.

For autonomous sewerage pipes that are smaller in size than central networks, the following standards apply:

In special conditions related to the terrain, a decrease in slope is allowed:

pipes 150 mm up to 0.008;
pipes 200 mm up to 0.007.

Storm water inlets are connected to the general system with a slope of 0.02.

Network depth

The minimum depth of the sewer pipeline depends on the thermal engineering calculation. The practice of operating utility networks in the area is also taken into account. The pipes are laid 0.3-0.5 m below the freezing point of the soil. The maximum depth depends on several factors:

pipe material;
type of soil;
pipeline diameter;
laying method.

Requirements for wells

Wells are an integral element of the sewer network, therefore the norms and rules for their installation are described in SNiP.

Manholes

To inspect the pipeline, special elements are installed - inspection wells. Their installation is carried out in two cases:

at pipe joints;
at the section where the direction of the pipeline changes.

SNiP determines the diameters of wells depending on the size of the pipes:

main line up to 600 mm – well 1000 mm;
pipeline from 700 mm and more - pipe size + 400 mm in length and 500 mm in width.

Inspection well

On straight sections of the gravity network, inspection structures are located every 35 m, for medium-diameter mains (500-600 mm) - 75 m, for large pipes (1500-2000 mm) - 200 m. The working part of the structure is equipped with a hanging ladder for descent.

Storm drain

Storm drainage serves to quickly drain rain and melt water. It can be open, closed or mixed. An open network consists of trays and channels, a closed network consists of storm water inlets and an underground pipeline, a mixed network is a combination of pipes and trays. To reduce the length of the system, the discharge is carried out into the nearest body of water or ravine.

When installing rainwater drainage systems, it is necessary to provide for the installation of structures for cleaning the most contaminated wastewater generated during rainstorms. For this purpose, sand traps, settling tanks and filters are installed. It is also recommended to design the possibility of using purified rainwater for irrigation and industrial needs.

Wastewater treatment devices

Storm water inlets

Storm water inlets are installed on slopes, pedestrian crossings and intersections. It is allowed to connect house drainage pipes and drainage networks to them. There are models with vertical, horizontal and combined grilles. Depending on the slope of the street, the distance between elements ranges from 50 to 80 m.