Stormwater runoff pollutes our rivers, lakes, and oceans. When rain hits concrete or asphalt pavement, it cannot seep into the soil and replenish our groundwater supplies. Instead, it absorbs the grease, oil, dirt, and animal droppings on the pavement, and carries it into storm drains. Stormwater is rarely treated to the same level as regular sewage, so these pollutants flow directly into our waterways.
If you have to maintain property in an urban area, you'll realize that there are lots of little bits of dirt between driveways, parking lots, sidewalks, and buildings. You could plant grass there, but it'd be a pain to mow it. If people walk on the grass, they'd wear down a trail and track dirt all over the place. Better to pave over everything, and save yourself the effort.
Solution: Take bits of cheap broken green glass (cullet), and crush it into pellets. Sieve it so you get a uniform gravel with no sharp shards. It would then be safe to handle, with no more risk of getting cut than if you were handling sand. Then, use it as a replacement for asphalt and concrete in low-traffic areas. Put down a layer of burlap or landscaping cloth, and then put down a thick layer of green pellets. It will look pretty and green, but won't need to be mowed like a lawn. During dry summers, it will stay green without watering. Rainfall will naturally seep down through it. If people walk on it, it won't track dirt everywhere. You can sell small bags of it at hardware stores for homeowners wanting to touch up that bit of dead grass near their sidewalk. You could sell truckloads to landscapers. In parks and cemeteries with light vehicle traffic, you could use it to make green-looking gravel roads for maintenance vehicles.