Stormwater Pond Alum Treatment

The City of St. Petersburg is seeking responses from qualified vendors to provide aquatic chemical application (alum) services to a residential stormwater pond. Services requested involved the procurement and application of liquid alum in a 26-acre stormwater pond in the City of St. Petersburg. Dosage is as prescribed by the city's management plan with an total application as 15,600 gallons of alum for a targeted dose rate of 9 mg Al/liter. Alum is used to target excess phosphorous in the lake and application rate is selected to cap the sediments and reduce nutrient flux to improve water quality. Access is available from the right-of-way, which is a residential neighborhood, to the shoreline of the stormwater pond and must be completed in no less than 48 hours. Application is typically done from small skiffs and workboats and evenly dispersed around the lake.