Audit of BOF Tree Guarantees

On April 28, 2011, The City of Chicago Office of Inspector General (OIG) released an audit of the City’s Tree Guarantee Process. The audit evaluated how well the City tracked and enforced its tree guarantees from January 1, 2008 through September 30, 2010. OIG found that the City had insufficient controls to prove that it was effectively using the guarantee provision when purchasing trees from suppliers.

The supplier agreements BOF has with its tree suppliers stipulate that all trees purchased by the City have a two year guarantee period. This ensures that suppliers, and not the City, pay for the replacement of deficient, unhealthy, or dead trees.

“Tree Guarantees are a smart way for the City to get what it pays for; however, in order for the Guarantee Process to work, the City has to have a good tracking mechanism in place,” said Inspector General Joe Ferguson. “That clearly wasn’t happening, and I hope BOF can use our findings to remedy the program.”

Specifically, the audit found:

  • BOF and suppliers reported substantially fewer tree guarantee replacements than expected based on the amount of trees planted during the audit period. 19,885 trees subject to guarantee during the audit period were purchased at a total cost of $10,797,555. 107 trees, approximately. 5% of the total trees planted, were replaced. Using a conservative estimated replacement rate of 5%, OIG estimates a potential loss of guarantee tree replacements of $481,641.
  • BOF and suppliers reported different numbers of trees planted during the audit period. OIG compared BOF records to invoices billed by suppliers and paid for by the City. During the audit period in 2008, BOF recorded 54 more trees planted than suppliers indicated they planted. For 2009, BOF recorded 620 more trees than suppliers said they planted. For 2010, suppliers reported 11 more trees than BOF said were planted.
  • BOF failed to properly track tree planting and tree replacements for over three years. BOF failed to ensure its mapping and tree tracking software systems properly interfaced, leading to an inability to properly track tree plantings and tree replacements.