https://www.healthywa.wa.gov.au/Articles/A_E/Algal-blooms
Algae are plants with a very simple cell structure, are mostly aquatic (living on, in or near water) and usually very small (microscopic) in size. However, some can form visible filaments (strings) and mats and some can grow quite large and appear plant like (for example, kelp). Some algae may float or attach to rocks, shells, and other plants.
https://www.healthywa.wa.gov.au/Articles/U_Z/Understanding-Septic-Tank-Systems
Most unsewered developments in Western Australia use septic tank systems to treat and dispose of sewage, also referred to as wastewater. Septic tank systems generally consist of one or two watertight cylindrical tanks called septic tanks and one or two sets of drainage receptacles which have holes in their sides and no base e.g. leach drains or soakwells.
https://www.healthywa.wa.gov.au/Articles/A_E/Cockburn-cement
Dust and odour from Cockburn cement has been the subject of contention in the local community for a number of years. Despite the improvements in stack (chimney) emissions, dust from exposed stockpiles, graded roads and open areas may be a source of dust in the community under certain wind conditions.