The final Douglas County chemical roundup of 2015, sponsored by Tri-County Health, is slated for Sept. 12 in Castle Rock.

Is your garage turning into a storage area for unwanted paint containers, old automotive fluids, tires, used batteries or burned-out light bulbs?

If you answered yes to any of those items, then mark your calendar.

On Sept. 12, the Tri-County Health Department will host its final chemical roundup of 2015 for Douglas County residents, offering a means to properly dispose of household waste that could otherwise contaminate people’s homes, the local water supply, air and landfills.

All roundup participants are asked to show proof of residence in Douglas County and pay $25 when dropping off chemicals. There will also be a free drop-and-swap area on site where people can take household cleaners, paint, car wax, antifreeze, fertilizer and garden products still in their original containers.

Accepted items to drop off include house and garden chemicals, automotive fluids, fluorescent light bulbs, fuels, propane tanks between one and 20 pounds, vehicle and household batteries, items containing mercury, car and pickup truck tires off the rim, and oil-based paint and paint products.

Items that will not be accepted include business and commercial waste, radioactive waste, electronic waste (computers, TVs, etc.), explosive waste, smoke detectors, waste containing asbestos, compressed gases other than propane, tractor tires, scrap metal and medical waste.

The final event of 2015 will take place on Sept. 12 at 175 Kellog Court in Castle Rock. Scheduled for 9 a.m. until 3 p.m.

For more information or to volunteer to help, please visit www.tchd.org/250/Home-Chemical-Waste or call Ellen Kennedy at 720-200-1592.