Cooper Environmental researchers have made major contributions to the development and application of source apportionment modelling and pioneered the use of receptor modeling methods in support of control strategies from federal to state implementation plans. We offer a complete set of services for receptor modelling studies including study design, data assessment and control strategies development. We perform source apportionment modelling using US EPA approved models, such as Positive Matrix Factorization, Chemical Mass Balance and UNMIX. A variety of multivariate analysis methods are also used to develop strong weight-of-evidence for source apportionment results. With over 40 years of combined experience and our continuing research in air quality management services, our clients are assured of the most innovative and contemporary approach to air quality data assessment.