indicated that there was a total of 520 wells installed at 405 households showing that water is urgently needed for domestic use (88.7%), and agricultural use (69.5%). There were 41.4% of the wells drilled since 2010 up to now and 74.3% of the wells drilled over 100 m. To get more water, particularly in dry seasons, the farmers applied large intake pipes (96.4% of the well’s pipe diameters were 49 and 60 mm) and illegally pumped (syringes pump, air pump, or rocket pump) which led to a decrease in groundwater levels and caused pressure on water source. Groundwater quality is within threshold values of national technical standards. Appropriate pumping technique was a suggestion to the farmers. Local authorities need to pay more attention to groundwater management in this area that help farmers use this resource.

0,6 m p.p.t. Przez to większość prac związanych z budową sieci kanalizacyjnej wykonywana jest poprzez metodę odwadniania gruntów, stosując np.: metodę igłofiltrów. Przy takich warunkach wodno-gruntowych, bardzo prawdopodobne jest występowanie zjawiska infiltracji. W artykule wykorzystano dwie metody do oszacowania wielkości infiltracji. Pierwsza z nich opierała się na zbilansowaniu ilości wody pobranej z sieci, z ilością ścieków odprowadzonych do systemu kanalizacji sanitarnej. Druga oparta na obserwacji wzrostu przepływu ścieków w czasie przejścia z okresu suszy do okresu o obfitych opadach. Obie z tych metod wykazały, że zjawisko infiltracji zachodzi oraz, że charakter dopływu infiltracyjnego różni się. Z przeprowadzonej analizy wynika, że procent infiltracji wynosi od 2% do 55% w zależności od występujących warunków.

to the construction of the sewage system is carried out using the soil drainage method, using, for example, the wellpoint method of dewatering excavations. With such water-ground conditions, infiltration is very likely to occur. The article uses two methods to estimate the size of infiltration - the first based on balancing the amount of supplied water with the amount of sewage discharged. The second is based on observing the increase of flow in wastewater network during wet weather and dry weather. Both methods showed that the infiltration phenomenon does occur and that the nature of the infiltration inflow differs. The analysis shows that the percentage of infiltration ranges from 2% to 55%, depending on the existing conditions.

processes and sea activity control process of closing and opening of rivers mouths. Although the closure of the mouth of big rivers has never been recorded, such tendency is observed at the end of dry season. In his way along seashore, one is passing by a countless number of coastal lagoons with their own drainage area. The lagoons are in the various stage of development in respect to sea-lagoon communication: Two-way communication. It is a rule during rainy season. Downstream communication only. Sea is open for lagoon, while lagoon is closed for the sea in the advanced stage of the construction of sand bar, excluding short period of high tides. Upstream communication only. The sand bar is so high that it prevents lagoon from reaching the sea. No water exchange between sea and lagoon. Liberian lagoons show unusual phenomenon of thermal inversion. There are several pits in lagoon where the temperature of the bottom layer is 3-6°C warmer tan the surface layer. The behavior of the Po river during dry season is described. The river of such size spans a gap between big Liberian rivers discharging into the sea and coastal lagoons with small catchment and in particular between fluvial and stemmed lagoons. The presented description of lagoon dynamics in respect to storage of mass, energy as well as thermal and salinity stratification shows that there are still some new challenging scientific problems, which calls for multidisciplinary investigation.