Royal Flush Septic Systems is the largest septic system installer in Collin and Grayson Counties, Texas. Since 2001, Royal Flush has installed over 2,000 septic systems and is the preferred provider for new homebuilders throughout the area. The company strives to maintain an outstanding working relationship with the county regulatory agencies. Royal Flush has been installing septic systems for over 20 years. Our staff have 50 years of excavation and land management experience.