NOVELTY - Integrated modular system for in-situ separation of solids in slurry resultant from a biogas plant for resource reutilization and recycling of water, comprises: e.g. perforated means to serve as trickling barrier for receiving slurry from biogas plant and allowing in-situ formation of progressively self-forming fine matrix of compacted solids contained in slurry; first hollow enclosure stacked above first hollow receptacle to form main filter which serves as scaffold for receiving perforated means; second receptacle capable of receiving first enclosure from above to form secondary filter.    USE - The integrated modular system is useful for in-situ separation of solids in slurry resultant from a biogas plant for resource reutilization and recycling of water.    ADVANTAGE - The integrated modular system: for in-situ separation of solids in slurry resultant from biogas plant is efficient and cost-effective; and provides easy scalability.    DETAILED DESCRIPTION - Integrated modular system for in-situ separation of solids in slurry resultant from biogas plant for resource reutilization and recycling of water, comprises: (a) perforated means to serve as a trickling barrier for receiving slurry from the biogas plant and allowing in-situ formation of a progressively self-forming fine matrix of compacted solids contained in the slurry; (b) a first hollow enclosure stacked above a first hollow receptacle to form a main filter which serves as a scaffold for receiving the perforated means, having the enclosure above outlines a void for accumulating the self-forming fine matrix of compacted solids contained in the input slurry and the receptacle below outlines a void for accumulating the clarified water that trickles under gravity from the enclosure above; (c) a second receptacle capable of receiving the first enclosure from above to form a secondary filter for removal of residual water in the cake of compacted solids contained in the first enclosure; and (d) conduits leading from the first and second receptacles to a storage tank for accumulating clarified water output of the integrated system and storing the same for later use. An INDEPENDENT CLAIM is also included for in-situ separation of solids in biogas plant slurry using the system, comprising loading biogas plant slurry to the main filter to allow in-situ formation of a progressively self-forming fine matrix of compacted solids contained in the slurry, when the first enclosure is full with accumulated solids, shifting the enclosure onto the second receptacle for resulting in the secondary filter, collecting clarified water trickled from the main and secondary filters in a storage tank for use later as recycled water for suitable value-added applications including watering of plants, and upon completion of cycle, harvesting the cake of solids accumulated in the first enclosure for use later for suitable value-added applications including use as a feedstock for fertilizer, where the output comprising product is the semi solid residue accumulated in the first receptacle containing 14-16% dry matter and second product is the clarified water output collated from the main and secondary filters which measures up to 50 vol/vol.% of the input slurry fed into the system.