How do rain gardens reduce pollution?

How do rain gardens reduce pollution?

• A. Increase infiltration and filter sediment and nutrients
• B. Increase runoff to storm drains
• C. Decrease soil absorption
• D. Raise water pH dramatically

Answer: (A)

Rain gardens reduce pollution by letting stormwater infiltrate into the ground through a layered soil mix and plant roots. As water sits briefly in the garden, sediment is physically trapped, and nutrients like nitrogen and phosphorus are taken up by plants or broken down by soil microbes. This filtration and biological uptake remove pollutants before they reach streams or groundwater. The result is less runoff and cleaner water downstream, which is why the best answer is that rain gardens increase infiltration and filter sediment and nutrients. They don’t raise runoff, they don’t reduce soil absorption, and they don’t dramatically change water pH.

Rain gardens reduce pollution by letting stormwater infiltrate into the ground through a layered soil mix and plant roots. As water sits briefly in the garden, sediment is physically trapped, and nutrients like nitrogen and phosphorus are taken up by plants or broken down by soil microbes. This filtration and biological uptake remove pollutants before they reach streams or groundwater. The result is less runoff and cleaner water downstream, which is why the best answer is that rain gardens increase infiltration and filter sediment and nutrients. They don’t raise runoff, they don’t reduce soil absorption, and they don’t dramatically change water pH.