Rules of water supply and sanitation: norms, balance calculation

Arrangement of communications during the construction or modernization of the house is a rather complicated and responsible process.

Already at the design stage of these two important engineering systems, it is necessary to know and strictly follow the rules. water supply and sanitation in order to avoid further operational problems and conflicts with environmental services.

In our material, we will try to deal with these difficult, at first glance, rules, and We will tell our readers why we need a water meter and how to calculate the volume correctly. water consumption.

The scope of the regulatory document

«Rules of cold water supply and sanitation"- this is the full name of the document approved on July 29, 2013. for N 644. Last revised - April 2018, changes and additions valid from 04/12/2018.

The rules determine the relationship of subscribers (consumers of services) and organizations supplying them, based on the conclusion of binding contracts.

The document also covers:

• service consumers - individuals, budget organizations, enterprises, etc .;
• algorithm for connecting objects to the CA (central systems);
• accounting of the released water, accounting of the allocated drains, quality of control;
• consumers who are obliged to take into account the discharge of effluents into the CA by measuring instruments;
• calculation of compensation for the discharge of excessively polluted effluents, the procedure for informing about changes in their composition and properties (filing declarations);
• standards, a mechanism for monitoring their use in practice, determining the size of the excess charge;

It must be thought out and provided, and if necessary, access to the subscriber’s water and sewage communications, to water sampling points and drains for sampling should be created.

Rules for the compilation of water balance

The calculation of the ratio of the volume of water consumption and wastewater is made for each object individually with an assessment of its specificity.

It takes into account the purpose of the building or room, the number of future users, the minimum (maximum) estimated water consumption for household or industrial needs. Water is taken into account all - drinking, technical, its reuse, waste water, storm discharge into the sewer.

Goals and objectives to be solved by making up the balance:

1. Obtaining permits for water consumption and drainage when connected to a centralized system;
2. The choice of water and sewer pipes of optimum diameter;
3. Calculation of other parameters - for example, power submersible pump, if we are talking about the use of a well in a private household;
4. Obtaining a license for the right to use natural resources (again, for the example described above - own independent source of water);
5. Conclusion of second-order contracts - let's say you rent a space in the office center, the subscriber of the city’s water supply channel is the owner of the building, and all tenants receive water from its (owner) water supply system and discharge it into its sewer drains. Consequently, the owner must pay the building.

The water balance is a table that shows the ratio of water used and wastewater for the year.

There is no uniform federal-level approved form for such a table, but the initiative is not prohibited, and water utilities offer their filling patterns for clients.

In general, the compilation of water management balance for a small enterprise will look like this:

• Step 1. We put in the first three columns consumer groups with numbering, name and quantitative characteristics.
• Step 2. We are looking for standards for each group on water consumption, using internal technical regulations (for the operation of bathrooms and showers), references (from of the personnel department on the number of staff, from the dining room on the number of dishes, from the laundry on washing volumes), SNiP 2.04.01-85 - “Domestic water supply and sewerage buildings. "
• Step 3. We calculate the total water consumption (cubic meters / day), determine the sources of water supply.
• Step 4. We enter data on water disposal, noting separately irretrievable losses (watering lawns, pool water, etc., which does not go down the drain).

As a result, a reasonable difference between water disposal and water consumption can be 10-20%. The value of up to 5% is neglected, as a rule, and it is considered that the discharge into the sewer is equal to 100%.

Installation requirements for water meters

Accurately calculated water balance is a significant argument in the justification water fees. With it, you can try to challenge the supplier’s overestimated average tariffs, which include the cost of water loss in accidents in the pipeline, repairs, leakages in the basements, prove the need to take into account the seasonality factor and etc.

Practice shows, however, that the truth is not easy to achieve, and the best way out is installation of a water meter. According to his testimony, the amount of water used is determined to a drop.

In the presence of a counter payment for water is simplified: indicator multiplied by the price of 1 cubic meter of water. So, counting devices are mounted both on pipes with cold, and with hot water. It is important to monitor the integrity of the seals and periodically (once in several years) to check the condition.

For sewer systems, metering of discharge water is not provided (except for specific industrial enterprises). Their volume is equal to the volume of water consumed.

Common House and individual water meters contribute to saving housing costs. The amount of money in the receipt directly depends on the amount of saved cubic meters. Mass implementation of water meters also disciplines employees of water utilities. It is no longer possible to write off uncontrollably the losses from water losses on worn water and sewer networks to the consumer.

Water supply rules are supplemented by provisions for the installation of meters and their commissioning. You can install the device with your own hands and invite the master to the house for sealing.

There are two requirements for installing a water meter:

1. Put a pre-filter in front of the device to protect it from small debris in tap water.
2. Use a check valve at the outlet of the meter in order to prevent its promotion in the opposite direction.

Before purchasing a meter, you need to check its passport data and check it with the numbers on the case and the device details. You should also inquire about conducted verification and make sure the installation kit is available.

Examples of calculating water consumption and drainage

The load on pipelines and devices that provide uninterrupted supply of water to various sanitary equipment (kitchen sink, faucet in the bathroom, toilet, etc.), depends on the performance its expense.

In the calculation of water consumption is determined by the maximum water consumption per day, hour and second (both total and cold and hot separately). For wastewater there is a method of calculation.

On the basis of the obtained results, the parameters of the water supply system are established according to SNiP 2.04.01-85 - “Internal water supply and sewerage of buildings"[1] and some additional ones (diameter of the passage of the counter, etc.).

Example 1: calculating the volume by the formulas

Initial data:

Private cottage with a gas water heating column, it is home to 4 people. Sanitary equipment:

• faucet in the bathroom - 1;
• toilet bowl with flush tank in the bathroom - 1;
• faucet in the kitchen sink - 1.

It is required to calculate the water consumption and select the cross-section of the supply pipes in the bathroom, bathroom, kitchen, and the minimum diameter of the inlet pipe - the one that connects the house with a centralized system or source water supply. Other parameters from the mentioned building codes for a private house are not relevant.

Payment:

1. Water consumption (max) in 1 sec. calculated by the formula:

Qsec = 5 × q × k (l / s)where:

q - water consumption in 1 sec. for one device according to item 3.2 [1]. For the bathroom, bathroom and kitchen - 0.25 l / s, 0.1 l / s, 0.12 l / s, respectively (Appendix 2 [1]).

k - coefficient from Annex 4 [1]. Determined by the probability of plumbing (R) and their number (n).

2. Define R:

P= (m × q₁) / (q × n × 3600)where

m - people m = 4 people;

q₁ - the total maximum rate of water consumption per hour of greatest consumption, q₁ = 10.5 l / h (Appendix 3 [1], the presence in the house of plumbing, bathroom, gas water heater, sewage);

q - water consumption for one device in 1 sec .;

n - the number of plumbing units, n = 3.

Note: because the value q different then replace q * n summation of the corresponding figures.

P = (4 × 10.5) / ((0.25 + 0.1 + 0.12) × 3600) = 0.0248

3. Knowing P and ndefine k according to table 2 of annex 4 [1]:

k = 0,226 - bathroom, bathroom, kitchen (based on n × P, i.e. 1 × 0.0248 = 0.0248)

k = 0.310 - cottage as a whole (based on n × P, i.e. 3 × 0.0248 = 0.0744)

4. Define Q_sec:

bathroom Q_sec = 5 × 0.25 × 0.226 = 0.283 l / s

a bathroom Q_sec = 5 × 0.1 × 0.226 = 0.113 l / s

kitchen Q_sec = 5 × 0.12 × 0.226 = 0.136 l / s

cottage as a whole Q_sec = 5 × (0.25 + 0.1 + 0.12) × 0.310 = 0.535 l / s

So, the water flow received. We now calculate the cross-section (internal diameter) of pipes by the formula:

D = √ ((4 ×Q_sec) / (PI × V)) (m)where:

V - water flow rate, m / s. V = 2.5 m / s according to paragraph 7.6 [1];

Q_sec - water consumption in 1 sec., M³/ sec.

bathroom D = √ ((4 × 0.283 / 1000) / (3.14 × 2.5)) = 0.012 m or 12 mm

a bathroom D = √ ((4 × 0.113 / 1000) / (3.14 × 2.5)) = 0.0076 m or 7.6 mm

kitchen D = √ ((4 × 0.136 / 1000) / (3.14 × 2.5)) = 0.0083 m or 8.3 mm

the cottage as a whole D = √ ((4 × 0.535 / 1000) / (3.14 × 2.5)) = 0.0165 m or 16.5 mm

Thus, the bathroom requires a pipe with an internal cross section of at least 12 mm, for a bathroom - 7.6 mm, a kitchen sink - 8.3 mm. The minimum diameter of the inlet pipe for the supply of 3 santehpriborov - 16.5 mm.

Example 2: simplified definition

Those who are afraid of an abundance of formulas can make a simpler calculation.

It is believed that the average person consumes 200-250 liters of water per day. Then the daily consumption of a family of 4 people will be 800-1000 liters, and monthly consumption - 24000-30000 liters (24-30 cubic meters). m). In private houses in the courtyards there are swimming pools, summer showers, drip irrigation systems, i.e. part of the water consumption is irrevocably imposed on the street.

Water consumption is increasing, but still there is a suspicion that the approximate standard of 200-250 liters is unreasonably high. And indeed, after installing water meters, the same family, without changing their household abilities, winds 12-15 cubic meters across the counter. m, and in economy mode it turns out even less - 8-10 cub. m

The principle of drainage in a city apartment is this: how much we consume water, so much and drain it into the sewer. Consequently, without a counter, up to 30 cu. m, and with a counter - no more than 15 cu. m. Since in the private sector not all the water consumed flows back into the sewer, it is true it would be in the calculation of water disposal to use a reduction factor: 12-15 cubic meters × 0.9 = 10.8-13.5 cubic meters. m

Both examples are conditional, but a table with this calculation of water consumption and discharge, which only a qualified engineer can do, should be in the presence of all economic entities (enterprises, housing), engaged in the collection of water for drinking, sanitary and hygiene, production needs and discharge drains

Responsibility for the accuracy of the data used in the calculation rests with the water user.

Rationing - the main rule of any calculations

Each region has its own norms of water consumption (drinking, for sanitary needs, in everyday life and household). This is due to different geographical location, weather factors.

Take the daily rate of volume parameters of water consumption and drainage, distributed to the needs of household and household. Do not forget that they are the same for the supply and discharge of water, but depend on how well the dwelling is arranged.

Regulatory values ​​of water consumption:

• with water stand - from 40 to 100 liters per person;
• apartment type residential building without baths – 80/110;
• the same with baths and gas heaters – 150/200;
• with centralized hot and cold water – 200-250.

To care for pets, poultry, there are also norms for water consumption. They include the costs of cleaning pens, cages and feeders, feeding, etc. 70-100 liters are provided for a cow, 60-70 liters for a horse, 25 liters for a pig, and only 1-2 liters for a chicken, turkey or goose.

There are rules for the operation of vehicles: tractor equipment - 200-250 liters of water per day, car - 300-450. It is planned to plan water flow for fire fighting for all buildings and structures, regardless of the operational purpose.

There is no exception even for garden societies: the rate of water consumption for extinguishing fire outside is 5 liters per second for 3 hours, internal ignition is from 2 to 2.5.

Water for fire extinguishing taken from the water supply. On the water pipes in the wells put fire hydrants. If this is not technically feasible or unprofitable, then you will have to take care of a reservoir with a supply of water. This water should not be sent for other purposes, the recovery time in the reservoir is three days.

Irrigation water consumption per day: 5-12 l / m² for trees, shrubs and other plantations in open ground, 10-15 l / m² - in greenhouses and greenhouses, 5-6 l / m² - for lawn grass and flower beds. In industry, each industry has its own characteristics of rationing water consumption and removal of wastewater - water-intensive are pulp and paper production, metallurgy, petrochemistry, food industry.

The main purpose of rationing is to economically justify the norms of water consumption and drainage in order to rational use of water resources.

The relationship of water users and service provider

By entering into a contractual relationship with the organization of plumbing, you become a consumer of water supply / wastewater services.

Your rights as a user of the service provided:

• require the supplier to continuously provide appropriate services (regulatory pressure, safe for life and health, its chemical composition);
• qualify for the installation of water meters;
• require recalculation and payment of penalties in the case of providing services in incomplete (the act must be drawn up within a day after the application is submitted);
• terminate the contract unilaterally, but subject to notification of this for 15 days and full payment of services received;

The subscriber has the right to receive payment information free of charge (personal account status).

The list of rights of the second party:

• stop (with prior notification for several days) fully or partially supply of water and wastewater in case of unsatisfactory technical condition of water supply networks and sewage;
• to demand admission to the client’s territory for the removal of gauges, checking seals, inspecting plumbing and sewage systems;
• conduct scheduled preventive maintenance on schedule;
• turn off the water debtors to pay;
• stop water delivery without warning in case of accidents, natural disasters, power outages.

Disputes and disagreements are resolved through negotiations or in court.

Conclusions and useful video on the topic

How to correctly calculate the water consumption:

Economical water. Water consumption is reduced by 70:

In order to perfectly understand the intricacies of water supply and drainage from the point of view of the rules, one must be an expert with specialized education. But everyone needs general information to understand how much water we get and how much we pay for it.

Economical water consumption and bringing the specific consumption to the level of true needs are not mutually exclusive concepts, and we should strive for this.

If, after studying the material, you have questions about calculations or water consumption rates, please ask them in the comments. Our experts are always ready to clarify incomprehensible moments.