Field studies of stormwater pond dynamics in response to storm events at horticultural operations were carried out to determine the critical points at which farmers must manage their collection ponds to protect the environment. For most horticultural greenhouse operations, stormwater ponds essentially collect rainwater from the greenhouse roofs, and may collect subsurface drainage water from adjacent land or the greenhouse production facility. Continuous as well as strategic monitoring was carried out at three floriculture greenhouse sites over the 2014 season, collecting information on volumes, overflows, meteorological data, and composition of pond water and stormwater overflows. This project is the first phase in developing Best Management Practices for producers to size, design, and monitor their stormwater management systems to adapt to changes in size, intensity, frequency, and variability of growing season storm events predicted by current climate change models. The development of a coherent management and sampling strategy is of value to farmers, who are looking at whether their ponds are designed and operating properly, and are seeking to comply with environmental ministry requirements.

This project was intended to provide guidance on innovative water treatment technologies for the horticulture sector in Ontario. The scope of the project included: installation of 2 portable hybrid treatment systems (HTS) to test the operational parameters needed to treat (i.e. clean) floriculture greenhouse and nursery wastewater so that it can be either safely discharged to the environment, or rendered suitable for re-use within the operation, installation of 2 permanent hybrid treatment systems (HTS), one at a container nursery and one at a flower greenhouse, using information obtained from the pilot systems as well as previous studies, and development of a Guidance Document for growers to help them make informed decisions regarding water management and treatment options. The Hybrid Treatment System represents a flexible tool for water treatment, particularly in situations where there is a desire to recirculate or discharge very clean water. Removal rates in each of the selected media are dependent on temperature, flow rate (hydraulic retention time), and nutrient concentration. Temperature is particularly important for the woodchip cells, since these are primarily a biological treatment. For optimum performance these systems need to be designed on the basis of projected daily water volumes, concentrations for treatment, and expected temperatures over the entire production period. While these systems do require a significant footprint outdoors, they can be tailored to match the volumes and fluctuations of a particular operation. And in many cases, the surface of the treatment can be used as a production area, but machine traffic should be avoided. It is highly recommended that growers conduct a self-assessment of the farm prior to choosing a water management solution.