From Big Medical Encyclopedia

DRAIN — system of constructions for organized removal from the territory of the settlement of a pla of the industrial enterprise of rain, thawed, drainage and other types of surface waters in natural reservoirs.

Appeared in 2500 — 6000 years BC century (India, Egypt, Ancient Greece, Rome). The first water outlet canals in Russia found at excavation belong to 11 century (Novgorod).

It is provided at a design of the settlement as the obligatory element of improvement providing free branch from its territory of a superficial drain century. In some cases V.'s use for removal of the low-contaminated production waters is projected, the release to-rykh in a reservoir without cleaning meets requirements «Rules of protection of surface waters from pollution by drain waters».

Fig. 1. The scheme of the stormwater drainage system on the city highway: 1 — a viewing well; 2 — the carriageway; 3 — the drain inlet connected by a pipe to a viewing well and the general system of a drain.
Fig. 2. Livnepriyemny well of Recreation center-7: 1 — a livnepriyemny lattice (shooters specify the direction of the movement of water).

Dignity. value B. is defined by need of bystry removal from the territory of the settlement of waters of a superficial drain, prevention of flooding and bogging of streets, yards, underground communications.

The closed and open circuits of Century are applied. The open circuit consists of the roadside ditches, trays, ditches which are taking away a superficial drain to the rivers, ponds and other reservoirs which are not used by the population near the place of release. Places of production of the taken-away waters in a reservoir shall be defined in each case depending on a dignity. situation and nature of use of a reservoir. In the industrial cities with the asphalted streets and the yards within the city V. with the closed network (on certain sites of the city there can be a mixed system) is under construction.

Along with the taking-away network B. are a part of the system the internal drains collecting an atmospheric precipitation from roofs, viewing wells and drain inlets of a different design on streets (fig. 1 and 2). Sometimes under the terms of a land relief perepuskny wells and the regulating tanks get a job on the taking-away network.

The closed system B. has a dignity. advantages since excludes a stagnation of water on streets, difficulties in the movement of pedestrians, accumulation in the lowered places of garbage and silt, it is more convenient for cleaning. The quantity of a drain, on a cut is calculated network B., is determined totally by design calculations of all drains which are subject to branch through a drain. Emergency dumpings crude production and economic and fecal shall not be provided in projects of network B. drain waters (see).

The composition of the surface waters allocated for V. hesitates in considerable limits and is defined by the following major factors: degree of the impurity of a rain drain depending on intensity and duration of a rain, character and extent of pollution of free air; improvement and dignity. condition of the territory of the settlement, industrial enterprises; organization dignity. cleanings of the territory; the nature of use of page - x. territories; quantitative and quality indicators of the pollution arriving with production and other waters. Dignity. conditions and places of releases from V. in a reservoir are defined by the existing «Rules of protection of surface waters from pollution by drain waters».

Century the dignity is an important object precautionary and current. supervision, to-rogo enters tasks: a) improvement of territories by the organization of assignment of contaminated waters; b) the choice of the place of production of storm waters in a reservoir outside their influence on zones of water use of the population; c) the prevention of pollution of a reservoir within the settlement the taken-away drain waters; d) definition of conditions of dumping of production drains into the stormwater drainage system and a construction for their prerefining (oil and maslolovushka, settlers, catchers of explosive substances, etc.). Current dignity. supervision comes down to a dignity. to control of structure and influence on a reservoir of the drains dumped on the stormwater drainage system in dry weather and during a rain, to taking a step to elimination of the found shortcomings.

Exponents of impurity of the waters dumped in a reservoir through V. are to a certain extent criterion a dignity. conditions of territories, with to-rykh the drain gathers.

See also Improvement of the inhabited places .

Bibliography: Zhukov A. I., etc. Sewerage, page 160, M., 1969; Molokov M. V. and Sh both about r and G. G's N. Rain and all-floatable sewerage, M., 1954; The Guide to utility hygiene, under the editorship of F. G. Krotkov, t. 2, page 667, M., 1962.

H. N. Kvitnitskaya.