The California Water Boards' Annual Performance Report - Fiscal Year 2014-15

PLAN AND ASSESS: SEWAGE SPILLS

GROUP:

SANITARY SEWER OVERFLOWS
(Collection Systems)

MEASURE:

SIZE OF SEWER SYSTEMS
SEWAGE SPILLS

MESSAGE:

56 percent of regulated facilities did not report a sewage spill in FY 2014-15. Of the spills that did occur, 64 percent of the sewage spilled reached surface waters.

*KEY STATISTICS FOR FY 2014-15*
Facilities reporting no spills:	612
Facilities reporting 6 or more spills:	134

MEASUREMENTS - Data last updated on: 10-12-2015 (8:22 am)

Region	Facilities Regulated Under SSO Program	Facilities With No Spills Reported	Total Sewage Spill Events During FY 13-14	Number of Facilities Reporting One Sewage Spill	Gallons Spilled for Facilities with One SSO	Number of Facilities Reporting 2 to 5 SSOs	Gallons Spilled for Facilities Reporting 2 to 5 SSOs	Number of Facilities Reporting 6 or More SSOs	Gallons Spilled for Facilities Reporting 6 or More SSOs
1	70	43	71	27	23,105	10	151,916	4	39,915
2	133	35	1,173	98	94,501	24	399,604	50	5,723,702
3	104	59	201	45	75,847	18	252,025	13	138,141
4	144	67	448	77	113,647	35	396,714	16	348,017
5F	157	126	108	31	6,102	13	144,355	4	7,786
5R	51	39	56	12	348	5	34,325	3	115,970
5S	181	103	2,084	78	110,038	30	205,975	20	809,748
6A	22	13	36	9	5,150	4	22,010	3	2,108
6B	50	33	49	17	11,436	6	287,898	1	3,081
7	32	22	22	10	3,350	3	220,100	1	2,700
8	87	44	142	43	10,501	21	201,627	8	671,154
9	62	28	190	34	11,005	13	37,377	11	645,872
TOTAL	1,093	612	4,580	481	465,030	182	2,353,926	134	8,508,194

Region	Volume of Sewage Spilled	Volume Reaching Surface Water	Percent Reaching Surface Water
1	214,936	202,073	94%
2	6,217,807	5,764,776	93%
3	466,013	339,471	73%
4	858,378	450,864	53%
5F	158,243	1,970	1%
5R	150,643	106,104	70%
5S	1,125,761	122,152	11%
6A	29,268	19,000	65%
6B	302,415	3,606	1%
7	226,150	375	0%
8	883,282	114,413	13%
9	694,254	176,170	25%
TOTAL	11,327,150	7,300,974	64%

WHAT THE MEASURE IS SHOWING

In Fiscal Year (FY) 2014-15, 134 facilities regulated under the SSO Program reported that 75 percent of the total volume of sewage spilled statewide. Of the remaining facilities regulated under the SSO Program, 612 of the 1,093 collection systems regulated (56 percent) did not report any spills during the FY.

WHY THIS MEASURE IS IMPORTANT

SSOs often contain high levels of suspended solids, pathogenic organisms, toxic pollutants, nutrients, oil, and grease. Typical consequences of SSOs include the closure of beaches and other recreational areas, inundated properties, and polluted rivers and streams. This measure tracks the reporting required by the Statewide Sanitary Sewer Order and will help to determine if the sewer system management plans (SSMP), also required by the order, are contributing to a reduction in the number of SSO events.

TECHNICAL CONSIDERATIONS

Data source: CIWQS. Period July 1, 2014 to June 30, 2015.
Unit of Measure: Average Number of Spills per 100 miles: Measures the number of sewer overflows per 100 miles of sewer lines. Average Volume of Spills per 100 miles: Measures the volume in gallons of sewer overflows per 100 miles of sewer lines.
Data Definitions: Sanitary Sewer: A pipe or conduit (sewer) intended to carry wastewater or water-borne wastes from homes, businesses, and industries to the POTW. Sanitary Sewer Overflows (SSO): Untreated or partially treated sewage overflows from a sanitary sewer collection system.
References: Information on the Sanitary Sewer Overflow Reduction Program
The Sanitary Sewer Overflows Incident Map
The Interactive SSO Report

GLOSSARY

Sanitary Sewer Overflow

A sanitary sewer overflow (SSO) is any overflow, spill, release, discharge or diversion of untreated or partially treated wastewater from a sanitary sewer system. SSOs do not include overflows from blockages or other problems within a privately owned lateral.

Sanitary Sewer Overflow Reduction Program

In May, 2006, the State Water Board adopted a Statewide Sanitary Sewer Order (ORDER NO. 2006-0003-DWQ) to address the issue of SSOs in a consistent and uniform manner statewide. Through the order, California became the first state in the nation to implement a program focused on the regulation of sanitary sewer systems. Sanitary sewer system agencies covered under the order, referred to as Enrollees, are required to report all SSOs for which their agency has responsibility into the State Water Board’s SSO database. Enrollees are also able to report sewage discharges from privately owned laterals or collection systems, for which the Enrollee has knowledge of the event but is not responsible, on a voluntary basis.

( Page last updated: 9/29/15 )