Phosphate Discharge into Laguna de Santa Rosa
River Watch vs. City of Santa Rosa
Case Number: C04 4195 EMC
Date filed: July 15, 2004
On July 15, 2004, River Watch notified Mr. Scott Stinebaugh, Deputy Director - Utilities Operations of the following violations:
- EXCESS DISCHARGES OF PHOSPHATES: The Laguna de Santa Rosa is listed by the CWA § 303(d) as impaired for nutrients including phosphate. The City is the single, largest contributing source of phosphate to the Laguna de Santa Rosa. By discharging a prohibited quantity of phosphate the City is causing contamination and a nuisance as defined by California Water Code ("CWC") Section 13050. By discharging a prohibited quantity of phosphate, the City is adversely affecting beneficial uses as those uses are defined in the CWA, the CWC, the Basin Plan and in CFRs. Phosphate is a biostimulant. The phosphate discharged by the City causes a nutrient load which exceeds the budget for the Laguna. This eutrophication results in algal blooms and the proliferation of surface plants. The algae and surface plants reduce, and in some cases destroy, the quality of the habitat for salmonids. The surface plants are known to harbor mosquitos including species which carry disease. One of the problems with phosphate is that it accumulates in the bottom deposits. Thus, when the bottom deposits are disturbed it causes prohibited amounts of phosphate to be discharged into the Laguna. In some case the discharges by the City actually cause resuspension of phosphate.
- LEAKING WASTEWATER PONDS: The City has numerous ponds in which it stores and releases treated wastewater. A mass balance analysis reveals that these ponds are not integral and leak into the surrounding ground, groundwater and adjacent waters of the United States including the Laguna de Santa Rosa. Leaking ponds are neither described nor regulated in the City's Permit. Leaking ponds create a pollution, contamination or nuisance as defined by CWC Section 13050. As the ponds leak continually the City is discharging during the discharge prohibition period of May 15th through September 30th .
-DISCHARGES FROM COLLECTION SYSTEM: The City has an extensive collection system which is part of the Laguna Subregional Facilities. Discharges from the collection system occur continually due to breaks in the pipes carrying sewage. Discharges of raw or partially treated sewage create a health risk to the environment and to the public. A mass balance analysis indicates that losses of raw sewage occur in the system on a daily basis. This analysis is also supported by the inflow and infiltration ("I&I") data which shows an increase of flow during winter months indicating an influx of groundwater into the collection system due to breaks in the piping.
-HIGH CONTENT OF PHOSPHATES AND NITROGENOUS COMPOUNDS: The City maintains an extensive reuse program which includes approximately 6,236 acres of urban and agricultural land that is irrigated with treated sewage. Many of these lands lie adjacent to waters of the United States including the Laguna de Santa Rosa. Some of the irrigated properties include dairies and City property where animal and human waste is land spread. The treated sewage and solid wastes are high in nutrients. Treated sewage is often applied in excess of the natural capacity of the land to assimilate the nutrients creating an excess nutrient load which is washed from the fields during rains. The deposition of these wastes often occur at a time of the year when full assimilation and breakdown of the nutrients is incomplete prior to the first rains, or so called "first flush." During first flush excessive amounts of nutrients are washed from these fields into the Russian River, Laguna de Santa Rosa and other waters of the United States. Subsequent rains also carry prohibited amounts of nutrients to the effected waterways. Testing of discharge from these fields reveals a high content of phosphates and nitrogenous compounds. These discharges do not seem to be regulated.