Keep Mosquitoes Out of Your Septic Tank

Keep Mosquitoes Out of Your Septic Tank

Mosquitoes can spread germs that make people sick. Just one septic tank can produce thousands of mosquitoes. Mosquitoes get inside broken or unsealed septic tanks and lay eggs. After they hatch and grow, thousands of adult mosquitoes fly out of the broken or cracked septic tank each day.

Mosquitoes may be laying eggs inside your septic tank if it is:

  • Open or unsealed
  • Broken with cracks or spaces between the blocks
  • Missing a ventilation pipe screen cover
Mosquitoes in a septic tank, a septic tank with a broken concrete cover, and a ventilation pipe with no cover

Inspect and repair your septic tank to keep mosquitoes out

Check local regulations before repairing a septic tank on your own. You can work with a licensed septic tank installer to:

  • Seal the septic tank.
  • Repair cracks or gaps in the exterior walls of the septic tank using cement or expanding foam used for home insulation projects. Look for a product that is made to fill big gaps and is water resistant. Follow directions on the product label.
  • Cover vent or plumbing pipe openings using mesh with holes smaller than a mosquito.
  • Fill abandoned or unused septic tanks with dirt or gravel.
septic tank ventilation pipe with screen mesh, septic tank with concrete cover, and a septic tank sealed with PVC cap
Related Resources

Mosquito Control: Keep Mosquitoes Out of Your Septic Tank