Wireless sensor networks (WSN) technology has great potential to revolutionize many science and engineering domains. We present a novel environmental monitoring system with a focus on the overall system architecture for seamless integration of wired and wireless sensors for long-term, remote, and near-real-time monitoring. We also present a unified framework for sensor data collection, management, visualization, dissemination, and exchange, conforming to the new Sensor Web Enablement standard. Some initial field testing results are also presented.