See the press release issued October 10, 2017 by Santa Barbara County  and go to Recent Events below for more information.

Recent Events

In October and November 2017, the District has received and responded to numerous complaints of a “rotten egg” smell, or hydrogen sulfide (H2S), from an area in western Goleta. The District has identified the source as coming from irrigation from an agricultural operation. The District is in ongoing communication with the agricultural operation to better understand the causes and extent of the odors. 

For H2S odors, the District has two avenues of enforcement. The first is Rule 310 for Odorous Organic Sulfides. This rule is enforceable if all of the following criteria are met:

  • A single source is verified
  • Odors occur at or beyond the property line
  • Measurements of H2S exceed the rule’s concentration limit

The second option is Rule 303 for Nuisance. This rule is enforceable for H2S odors if all of the following criteria are met:

  • A single source is verified
  • The source is not an agricultural operation

Throughout the recent events, all of the levels measured by District inspectors were well below levels that allow the District to take further action.


There has been an increase in reports of sulfur odor in western Goleta. Some Goleta-area agriculture users rely heavily on private well water for irrigation. Historically, groundwater in this region contains sulfur compounds including hydrogen sulfide (H2S). With the recent drought, some ranchers are drilling deeper than before and are more likely to encounter groundwater containing H2S. H2S can be released from the water as a gas and create noticeable odors similar to a “rotten egg” smell. Use of sprinklers may increase the release of sulfur odors during irrigation. This part of the coast is also historically known for H2S odors.

H2S is a gas that produces a sulfur odor at low levels and health effects at higher levels. Sulfur odors are typically first detected at H2S concentrations of 0.01 ppm. According to the Occupational Safety and Health Administration (OSHA), health effects such as nausea, tearing, headaches, etc. may be experienced at H2S concentrations as low as 2 ppm. Detailed information regarding symptoms of H2S exposure at various concentrations can be found at the federal OSHA website.

If you or your family members are experiencing health effects from H2S exposure, it is recommended that you call 911, seal up your house, and remain inside as much as possible. If the odors continue to cause health effects, you should leave the area and move uphill until conditions improve. Sensitive individuals with more serious or persistent health effects should seek medical attention.

The District has a handheld Arizona Instrument Jerome (J-605) H2S Analyzer to measure H2S in the ambient air. The handheld analyzer’s detection range is 0.003 ppm–10 ppm. The District uses this equipment to determine levels of exposure and whether the District Odorous Organic Sulfides Rule thresholds have been exceeded (averaging 0.06 ppm H2S over 3 minutes, or 0.03 ppm H2S over 1 hour, at or beyond the property line).


To file a complaint with the District, call (805) 961-8810. Find more information on the District’s Complaints Process.

2016 Hydrogen Sulfide Odors

In October 2016, the District and other agencies investigated a release of H2S in the Ellwood area of Goleta. During the investigation, inspectors from County Environmental Health Services (EHS) identified the likely source as naturally occurring H2S that was released during drilling of a private agricultural water well. EHS suspended the well drilling permit until a mitigation plan was created. See County Officials Determine Water Well as Source of H2S Odor

The Venoco Ellwood Onshore Facility was not the source of the odors. Fence-line monitors installed at the Venoco Ellwood Onshore Facility measure H2S in the ambient air, regardless of the source. Six fence-line H2S monitors are strategically located at the Venoco Ellwood Onshore Facility based on potential sources of H2S releases at the facility; see map. The alarm threshold for these monitors is 0.3 parts per million (ppm) H2S.

See below for the Venoco Ellwood fence-line monitor data for times when the readings exceeded the alarm threshold of 0.3 ppm H2S. Dates and times not included in the tables below had readings of 0.0, 0.1 or 0.2 ppm H2S. Levels below 2 ppm H2S may be within the odor threshold, but are not within the health effects concentration ranges, according to OSHA.

Sunday, October 9, 2016 AM
Sunday, October 9, 2016 PM
Monday, October 10, 2016 AM
Monday, October 10, 2016 PM
Tuesday, October 11, 2016 AM

After the water well had been plugged, a District inspector took measurements of H2S in the ambient air with the handheld analyzer across multiple locations. The analyzer did not detect H2S in the ambient air at any of these locations.