Reminder: Certificates expire annually on March 1 for commercial manure applicators. Confinement site certificates are viable for three years ending on Dec. 31, with a two-month grace period for renewals. Commercial and confinement manure applicators who are renewing their certification need to complete the training or testing, and pay fees prior to March 1 to avoid a $12.50 late fee. The late fee does not apply to new applicants for a certificate.