Explain why surface waters are more susceptible to pollution than groundwater. Underground waters are considered

Explain why surface waters are more susceptible to pollution than groundwater. Underground waters are considered the purest. However, due to human economic activities, many sources of groundwater are also subject to depletion and pollution. Often, this pollution is so significant that the water from them has become unsuitable for drinking. The quality of water in most water bodies does not meet regulatory requirements. Long-term observations of the dynamics of surface water quality reveal a trend of increasing the number of sections with high pollution levels (more than 10 MPC) and the number of cases with extremely high concentrations (over 100 MPC) of pollutants in water bodies. The condition of water sources and centralized water supply systems cannot guarantee the required quality of drinking water, and in some regions (Southern Urals, Kuzbass, some Northern territories), this condition has reached a dangerous level for human health. Sanitary and epidemiological surveillance services constantly note high pollution of surface waters. About 1/3 of all pollutants are introduced into water sources with surface and stormwater runoff from areas with unsanitary conditions, agricultural facilities, and lands, which affects the seasonal deterioration of drinking water quality, annually observed in major cities. As a result, water is hyperchlorinated, which, however, is unsafe for the health of the population due to the formation of chlororganic compounds. One of the main pollutants of surface waters is oil and oil products. Oil can enter water as a result of natural seepage in areas of occurrence. But the main sources of pollution are associated with human activity: oil production, transportation, processing, and the use of oil as fuel and industrial raw materials. Among the products of industrial production, toxic synthetic substances occupy a special place in their negative impact on the aquatic environment and living organisms. They are increasingly used in industry, transport, and communal services. The concentration of these compounds in wastewater is usually 5-15 mg/l, while the MPC is 0.1 mg/l. These substances can form a layer of foam in water bodies, especially noticeable at rapids, cascades, and locks. Foam formation for these substances occurs already at a concentration of 1-2 mg/l due to the inability of microorganisms to degrade many synthetic substances, self-purification of water bodies occurs very slowly.