A residential housing development project involves significant earthmoving on a challenging site with varied topography and soil types (clay, sand, and some bedrock). The project spans over 1,000 square metres of disturbed area. What is the most comprehensive and technically sound erosion and sediment control plan given the site's complexity?

Question: A residential housing development project involves significant earthmoving on a challenging site with varied topography and soil types (clay, sand, and some bedrock). The project spans over 1,000 square metres of disturbed area. What is the most comprehensive and technically sound erosion and sediment control plan given the site's complexity?

Answer options: ✅ A combination of silt fences, sediment traps, hydroseeding on final grades, and temporary diversion swales.

• Implementing only hydroseeding after all construction phases are complete.
• Relying solely on temporary straw bales placed at random intervals across the site.
• Installing a single, large sediment pond at the lowest point of the site.

Correct answer: A combination of silt fences, sediment traps, hydroseeding on final grades, and temporary diversion swales.

Explanation: Complex sites require a multi-faceted approach to erosion and sediment control. A combination of measures like silt fences, sediment traps, hydroseeding, and diversion swales addresses various runoff scenarios, soil types, and stages of construction, providing robust environmental protection as per OPSWA HEO training and engineering best practices.