Rules of water supply and sanitation: the calculation of the balance + flow rate and water consumption
Arrangement of communications in the construction or modernization of the house - 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 of water supply and sanitation in order to avoid further operational problems and conflicts with environmental services.
The scope of the regulatory document
"Rules for cold water supply and sanitation" - this is the full name of the document approved on 07.29.2013, for N 644. Last edited - April 2018, changes and additions are valid from 12.04.2018.
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:
- consumers of services - 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 effluent 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 the points of water extraction and drains for sampling should be created.
Rules for the compilation of water balance
The calculation of the ratio 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:
- Obtaining permits for water consumption and drainage when connected to a centralized system;
- The choice of water and sewer pipes of optimum diameter;
- Calculation of other parameters - for example, powersubmersiblepump, if we are talking about the use of a well in a private household;
- Obtaining a license for the right to use natural resources (again, for the example described above - own independent source of water);
- Conclusion of second-order contracts - let's say you rent a space in the office center, the owner of the building is a subscriber of the city's water supply system, and all tenants receive water from its (owner) water supply system and discharge drains into its sewers.Consequently, the owner must pay the building.
The water balance is a table that shows the ratio of water used and wastewater for a year. A single form approved at the federal level does not exist 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), certificates (from the personnel department about the number of staff, from the dining room about the number of dishes, from the laundry about washing volumes) Internal water supply and sewerage of 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 justifying payments for water use. You can try to challenge the supplier’s overestimated average rates, including the cost of water loss due to pipeline accidents, repairs, cellar leaks, prove the need to take into account seasonality factors, etc.
Practice shows, however, that the truth is not easy to achieve, and the best way out is to install a water meter. According to his testimony, the amount of water used is determined to a drop.
In the presence of a meter, the calculation for water is simplified: the indicator removed from the scoreboard is multiplied by the price of 1 cubic meter of water. Counters are mounted both on pipes with cold and hot water.It is important to monitor the integrity of the seals and periodically (once every few 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.
Individual and general water meters help save housing and utility 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 forsealing.
There are two requirements for installing a water meter:
- put in front of the device a coarse filter to protect against small debris in tap water;
- 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 must check its passport data and check it with the numbers on the case and the device details. It is also necessary to inquire about the verification carried out and make sure that 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 its flow rates.
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 according to SNiP 2.04.01-85 - “Internal water supply and sewerage of buildings”  and some additional ones (diameter of the passage of the meter, etc.) are established.
Example 1: calculating the volume by the formulas
Private cottage with a gas water heater, it is home to 4 people.Sanitary equipment:
- faucet in the bathroom - 1;
- toilet bowl withflushtank in the bathroom - 1;
- faucet in the sink in the kitchen - 1.
It is required to calculate water consumption and select the cross-section of the supply pipes in the bathroom, bathroom, kitchen, as well as the minimum diameter of the inlet pipe - the one that connects the house with a centralized system or water supply. Other parameters from the mentioned building codes for a private house are not relevant.
1. Water consumption () in 1 sec. calculated by the formula:
= 5 × q × k (l / s)where:
q- water consumption in 1 sec. for one device according to item 3.2 . For the bathroom, bathroom and kitchen - 0.25 l / s, 0.1 l / s, 0.12 l / s, respectively (Appendix 2 ).
k- coefficient from Annex 4 . Determined by the probability of plumbing (R) and their number (n).
P= (m × q1) / (q × n × 3600)where
m- peoplem= 4 people;
q1- the total maximum rate of water consumption per hour of greatest consumption,q1= 10.5 l / h (Appendix 3 , 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 valueqdifferent then replaceq * nsummation of the corresponding figures.
P = (4 × 10.5) / ((0.25 + 0.1 + 0.12) × 3600) = 0.0248
3. KnowingPandndefinekaccording to table 2 of annex 4 :
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. We define:
bath = 5 × 0.25 × 0.226 = 0.283 l / s
bathroom = 5 × 0.1 × 0.226 = 0.113 l / s
kitchen = 5 × 0.12 × 0.226 = 0.136 l / s
whole cottage= 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 ×) / (PI × V)) (m)where:
V- water flow rate, m / s.V= 2.5 m / s according to paragraph 7.6 ;
- water consumption in 1 sec., M3/ sec.
bathroomD= √ ((4 × 0.283 / 1000) / (3.14 × 2.5)) = 0.012 m or 12 mm
a bathroomD= √ ((4 × 0.113 / 1000) / (3.14 × 2.5)) = 0.0076 m or 7.6 mm
kitchenD= √ ((4 × 0.136 / 1000) / (3.14 × 2.5)) = 0.0083 m or 8.3 mm
the cottage as a wholeD = √ ((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 3santehpriborov- 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).In private houses in the courtyards there are swimming pools, summer showers, drip irrigation systems, i.e. part of the water consumption is irrevocably taken out onto 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 water we consume, we pour so much into the sewer system. 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 consumed water flows back into the sewage system, it would be fair to use a reduction factor in the calculation of water disposal: 12-15 cubic meters × 0.9 = 10.8-13.5 cubic meters. m
Both examples are conditional, but the table with the present calculation of water consumption and discharge, which can only be done by a qualified engineer, should be available for all business entities (enterprises, housing stock) that carry out drinking water, sanitary and hygienic,production needs and discharge of waste. 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 water consumption norms (drinking, for sanitary and hygienic 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 outdoor standpipe - from 40 to 100 liters per person;
- apartment house apartment house without baths - 80/110;
- the same with baths andgas heaters– 150/200;
- with centralized cold and hot water supply - 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 the flow of water for fire fighting for all buildings and structures, regardless of the operational purpose. Even for garden societies, there is no exception: 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 it 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 / m2for 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-intensiveare pulp and paper production, metallurgy, petrochemistry, food industry.
The main purpose of rationing is to economically justify the norms of water consumption and drainage for the purpose of rational use of water resources.
The relationship of water users and service provider
By entering into a contractual relationship with the organization of water supply and sewerage facilities, you become a consumer of the water supply / drainage service.
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 volume (the act must be drawn up within a day after the application is submitted);
- terminate the contract unilaterally, but subject to notification of this within 15 days and full payment of the 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;
- require admission to the client’s territory for the removal of indicators of gauges, checking seals, inspecting plumbing and sewage systems;
- conduct scheduled preventive maintenance on schedule;
- turn off the water debtors to pay;
- stopwater deliverywithout 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 this should be sought.