Absorbing Well

ABSORBING WELL, a well designed for the absorption of fecal, sewage, and drainage waters by the soil. It is constructed either in the form of a pit of greater or lesser depth with permeable walls and bottom, or in the form of a shaft or bored well. In the latter case, the absorbing well is brought down to the water-bearing horizon. The construction of absorbing wells is a gross violation of sanitary requirements for the protection of soil water and soil from pollution and threatens very serious sanitary consequences for populated areas that use water supply sources connected with such contaminated soil layers. In some cases, the influence of an absorbing well can extend over a very large distance. A known case is the contamination of the Paris water supply by absorbing wells of surrounding farms, with the contamination penetrating through fractured limestone rocks to a very great depth. Khetsrov and Mikhailovskaya, during investigations of artesian wells in Moscow, discovered very high contamination in some of them. In the water from the lower Carboniferous layer (the 3rd artesian), they detected (in milligrams per 1 liter of water): oxidizability up to 6.6, chlorine up to 227.0, ammonia up to 3.8. This phenomenon can be explained by the presence in Moscow of a large number of absorbing wells, which served as abandoned artesian wells as well as drainage wells. The contamination of the water in shallow wells by absorbing pits for sewage and slop water represents an evil that sanitary supervision very frequently has to combat. In the USSR, there is as yet no general sanitary law for the protection of water and soil; however, by the "Sanitary Rules for the Collection, Disposal, and Treatment of Sewage and Refuse in Non-Sewered Populated Areas of the Urban Type", issued by the People's Health Commissariat and the People's Commissariat of Internal Affairs in 1927, absorbing wells are prohibited in the RSFSR. In addition, absorbing wells are prohibited by local mandatory regulations in many places. First and foremost, absorbing wells in water supply protection zones, where their existence is especially dangerous, must be eliminated. In view of the fact that any poorly constructed cesspool or slop pit with permeable walls can act as an absorbing well and contaminate the soil and soil water, it is necessary to impose definite sanitary requirements on their construction and to inspect whether a given receiver is passing dirty water into the soil. In doubtful cases, it is recommended to fill the receivers with clean water and determine the degree of permeability of the walls and bottom by the change in liquid level. It should be borne in mind here that the soil around old absorbing wells can be so silted up that percolation proceeds very slowly, as a result of which it may not be detected during a superficial inspection. Particularly great attention should be paid to abandoned artesian wells and drainage wells. The latter should be permitted only in the absence of other methods of combating soil waterlogging and in the presence of a complete guarantee of non-contamination of the water supply sources of surrounding populated areas.