Research report on the dynamics of nitric compounds in different water levels of shallow wells, located in Pypliai, Kaunas District, is given in the thesis. Subject of research – water quality indicators: nitrates (NO3-), nitrites (NO2-) and ammonium (NH3). Aim of research – to define variation of nitrates concentrations in different water levels of shallow wells. Methodology: analysis of scientific literature; chemical water quality analyzes methods: spectral and electrochemical methods; statistical analysis using EXCEL, STATISTICA programs. Results of research: the results of scientific research showed, that nitrates concentrations in deeper levels of shallow wells vary differently; the tendencies of these variations depend on seasons. Seasons make no impact to nitrites and ammonium concentrations in deeper levels of shallow wells. The following statistically relevant water indicators were determined to influence nitrate concentration in shallow well water: oxygen quantity and electrical conductivity. Nitrite concentrations are inversely proportional to oxygen amount. Ammonium concentrations depend on organic compound quantity. Statistically relevant links between nitrites and ammonium were estimated.

After approximately 25 years of using open drains in the Lewiston Area, Utah, the water table has not changed appreciably from what it was in 1921 when Hart and Adams (4) conducted their drainage investigations. It is still only about three feet below the ground surface. This is not effective drainage, meeting neither of the two primary drainage requirements of an arid or semi-arid agricultural region, namely; preventing an accumulation of excessive water within the depth of soil required for optimum growth of plant root systems, and maintaining the water table at a depth below the ground surface greater than the maximum height capillary water can rise, carrying any harmful salts that may be present in solution.

From the Proceedings of the 1971 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 22-23, 1971, Tempe, Arizona / The southern bed of the ogallala aquifer is hydrologically isolated from all outside areas of recharge, requiring local precipitation for all natural recharge. Current withdrawals are so much greater than natural recharge that it appears that artificial recharge affords the only means of establishing at least a pseudo-balance. A number of observation wells were drilled at Texas Tech University, and subsequently capped until recharge water became available. The initial recharge was 2.5 af over 12 days, at a rate of 120 gpm for about the first day, after which 60 gpm was relatively constant. Approximately 1 month later, 1.2 af were recharged over 3 days at rates ranging over 140-90 gpm. It became evident that a cavity was present at the bottom of the hole being recharged. On a later recharge occasion, the cavity seemed to have enlarged. During a period of 2 years more than 28 af of surface runoff water have been recharged through the shallow hole with increases in recharge rates for each subsequent recharge period. The nature of this phenomenon and the cavities are not understood. This may represent the long sought after answer to recharge of the aquifer, but much more extensive research needs to be done.