How did a citizen group called Friends of Arcata Marsh, Arcata, California, USA, help to improve water quality of the marshland using Integrated Waste Water Treatment ? Explain in four steps.

People from Arcata and biologists from Humboldt State University formed a group called FOAM (Friends of Arcata Marsh) and created an integrated wastewater treatment in the marshland to improve water quality.
The four steps of the integrated wastewater treatment are:
i. Conventional sedimentation
ii. Disinfectant is added
iii. To remove heavy metals use of marshland to neutralise the effect of toxic metal by using plants, algae, fungi and bacteria.
iv. Water is naturally purified as it flows from the marshland.