river and dry branch and algae moss lichen. sewage or domestic wastewater or municipal wastewater

algae bad biological branch casing closeup combined community contaminants cure defective domestic drain dry duct dynamics effects effluent environment fragrance gutter heal impact leaf lichen litter management moss municipal natural nature odor outdoor people plant pollutant pollutants pollution product river runoff savor sewage sewer sewerage sewers smell snuff storm surface tainted thallophytic treat treatment tree tubing ulcerated untethered use waste wastewater water