Tip #2
/EZ BMPs!
There are a lot of fancy and expensive BMPs products out there to help reduce storm water pollutant discharge, but you should evaluate your situation before making a big purchase. The #1 way to control pollutants is source control which means controlling at where the pollutant came from, for example, metals foundry uses sand in their production process and the sand is stored outdoor and sign of sand track out are observed at the yard, therefore the most effective way is to change the process by storing the sand indoor or within a non-leaking covered container and do a weekly vacuuming at the yard, but sometimes changing the process is not that easy and requires time for the worker to adapt.
Another way is to take a look at your sample result and if your Total Suspended Solid (TSS) levels are high that means you might have a fighting chance before consider higher level BMPs such as metals filter socks, clarifier, retention basin and treatment system. Install BMPs such as gravel bags, straw-wattles, filter fabric with aggregate to help filter out some of the sediment. This works because metals and other contaminant tends to easily attach to dirt and if you can filter some of the dirt then you can reduce your total level of metals.
There are many cheap and creative ways to filter water. Here is a video example created by the Sacramento Student.
Here is another drain inlet protection sample created by HI DOT SC-2 using center block, filter fabric, and aggregate rocks.
