Contact your local health department to obtain a list of licensed or certified septic cleaning companies. Some states require septic service companies to be licensed, and most states and counties in the United States maintain a list of reputable companies.
Visit the Better Business Bureau's website at http://www.bbb.org/us/Find-Business-Reviews/ to search the list of licensed septic-cleaning companies in your area. Identify those that have received complaints.
Contact the septic cleaning companies and ask whether the company is bonded and insured. Make sure the company is licensed in your state if your state provides or requires a license.
Ask the septic cleaning companies about their pricing and compare the prices. Ask about discounts, such as a reduced service charge if you locate and dig to expose the access port to the septic tank.
Compare all these factors in making your decision of which septic cleaning company to hire. Avoid basing your decision solely on which company has the lowest prices.