This study aimed to evaluate the environmental quality of surface water of the Maricá Lagoon System through physicochemical, biochemical and microbiological parameters, in order to assess its environmental quality. Marine influence over the system was evidenced by the salinity and temperature gradients, where the most distant point, in Maricá Lagoon, presented the largest protein, lipid and biopolymeric carbon concentrations. Biopolymers, with predominance of lipids, presented a pattern that differs from the literature for coastal sediments. The concentration of thermotolerant coliforms characterised Maricá Lagoon and Boqueirão Channel as unfit for bathing (60.0 and 66.3 cells x mL(-1), respectively). The bacterioplankton in the system proved to be predominantly heterotrophic, a consumer of organic matter, with fermentative, denitrifying and sulfate-reducing metabolism. No esterase enzyme activity was detected, despite the presence of active metabolism, measured by the electron transport system (average of 0.025 µg O2 x h(-1) x mL(-1)). The bacterial biomass (autotrophic, heterotrophic and coliforms), bacterial respiratory activity and biopolymer parameters evinced a spatial degradation pattern in the Maricá Lagoon System, where the points with less water renewal are the most impacted.

Despite the significant improvements in water quality surveillance, irregular settlements and poor sanitation conditions have increased the impact and risk of health grievances over the past few decades. The aim of this study is to assess the development of the Drinking Water Quality Surveillance Program in Rio de Janeiro State, Brazil, by measuring the compliance with water sampling and 2014 analysis plans such as the residual free chlorine, turbidity and total coliforms / Escherichia coli tests (Health Ministry Ordinance, No. 2.914/11). Results have shown variation between counties and regions. The Middle Paraiba Region has shown the best results and the North and Northwest regions presented the worst ones. Since 2009, there has been improvements in the conducted quantitative analyses. These analyses indicate better program implementations, mainly focused on the test to measure the number of Coliforms / E. coli. An action plan based on intersectoral approach with the aim to assure high-quality access to the entire population was proposed to overcome the current problems in the program.

Thirty superficial sediment samples were collected in Guanabara Bay in order to identify new trophic state and environmental quality descriptors for coastal systems. A biochemical approach was used for analyzing the quality and quantity of sedimentary organic matter and metabolic bacterial activity. The samples were analyzed for particle size; organic matter, protein, carbohydrate, lipid, biopolymeric carbon, and bioavailable carbon levels; and bacterial metabolic activity. The results show a homogeneous spatial distribution for the anaerobic bacteria web and for biopolymers (carbohydrates>;lipids>;protein). The NE area of the bay displayed sediment lipid levels above 1 mg/g, indicative of organic sewage input. Spatial distribution of the superficial sediments in relation to other variables was not significant (p>;0.05). Biopolymers and labile organic matter showed a significant correlation with the average particle size of 80% of the fine particles. Despite the availability of labile organic matter, under the form of biopolymeric carbon, only 50% of the carbon was available to the trophic web. The bacterial consortia formed by sulfate reducing and denitrifying bacteria sustain the benthic trophic food web in Guanabara Bay.