The number of inspections performed annually has remained at a similar level since FY 2008-09. The data show that the number of inspections performed annually has remained consistent since fiscal year (FY) 2010-2011, with approximately 552 inspections performed annually. Inspections of closed landfills continue to make up the majority of inspections, as they have for the last seven years. Since 2000, the number of inspections performed at "all other" land disposal facilities declines annually. However, inspection trends are not equal in every region. For compliance purposes, some facilities are inspected more than once a year, so the total number of inspections performed may be greater than the total number of facilities inspected. It is the Water Boards' policy to ensure that facilities comply with Water Quality Control Plans, National Pollutant Discharge Elimination System (NPDES) permits, and waste discharge requirements (WDR). This policy is implemented through the Regional Water Board comprehensive self-monitoring and compliance inspection programs. Inspections are a primary tool used in determining and documenting compliance with WDRs. Inspection frequencies for WDR facilities are based on threats to water quality, with high risk sites and registered complaints receiving more attention. In addition to inspections, the Regional Water Boards assess facility compliance by reviewing self-monitoring reports submitted by the discharger and responding to complaints. The conditions described by self-monitoring data are validated through periodic inspections, which are the Water Boards' only means to evaluate system maintenance and observe unreported activities.