Monitored Industry Program Overview

Program Overview

Under the City of San José’s (City’s) Sewer Service and Use Charges (SSUC) for sanitary sewer service, “Monitored Industrial Users” are one of the three classifications of dischargers to the San José-Santa Clara Regional Wastewater Facility (RWF). The other two dischargers are “Residential Dischargers” and “Commercial, Institutional, & Light Industrial Dischargers.” In the current SSUC framework, Monitored Industrial Users are billed for actual flow and discharge of Total Suspended Solids (TSS), Ammonia (NH3), and Bio-Chemical Oxygen Demand (BOD) to the sanitary system. The remaining discharger classifications are billed on unit rates under the county tax roll.

The RWF receives industrial flow from approximately 20 Monitored Industrial Users in the South Bay area. The City of San José Environmental Services Department’s Monitored Industry Program conducts sampling, collects flow information, and compiles bills for Monitored Industrial Users throughout the RWF’s service area.

The program identifies and recommends new users and collects wastewater samples, industrial flow information, and other date points from Monitored Industrial Users. Additionally, the Environmental Services Department supports the other cities’ monitored industry programs in the RWF service area.

Program Implementation and Site Selection

The City’s SSUC follows State Revenue Program Guidelines for allocating costs to its customers. Under the State Revenue Program Guidelines, industrial users discharging more than 25,000 gallons per day (GPD) are required to have their rates allocated individually. This requirement sets the basis for putting users with more than 25,000 GPD into the Monitored Industry Program rather than billing them by subgroup on the tax roll.

In the City of San José, the Monitored Industry Program selects industrial sites based on discharging over 25,000 GPD or having a BOD concentration over 300mg/L. The City updates the Monitored Industry site listing on a yearly basis for adding or removing industrial users from the tax roll sewer billing each June.

Sample Collection and Long-Term Averages uses

The City currently utilizes a tiered monitoring approach for billing Monitored Industrial Users. Under this approach, most users are sampled for BOD, TSS, and Ammonia with the frequency of sampling and the application of long-term sampling averages dependent on the strength and loading from each user.

BOD is typically used as a screening criteria or “proxy” for overall “strength” of discharge. However, TSS and Ammonia may also be used in ascertaining an industry’s overall loading and setting a monitoring frequency. Users with higher loading are generally monitored more frequently, while users with low loading are monitored less frequently.

Below are descriptions of the various discharger classifications:

Extremely High Strength Dischargers

High Strength Dischargers

For dischargers designated as having “high strength” (100-4,999 mg/L of BOD) or “high loading” (100 to 999 lbs. of BOD per day), samples will be collected eight times per year (two times per quarter). The sample results collected will be averaged against a running 30-month average of past samples collected. Under this tier, users are billed monthly based on a “30-month running average.”

Variably High Strength Dischargers

Some dischargers occasionally straddle the “extremely high strength” and “high strength” designations above, either based on strength or loading. For these situations, the City has designated the use of a shorter, 12-month running average to account for production or discharge variability. For industrial users meeting this classification, samples will be collected eight times per year (two times per quarter). The sample results collected will be averaged against a 12-month running average. Under this tier, users may be billed monthly based on a “12-month running average” until a more-appropriate averaging approach can be identified.

Low Loading Dischargers

The remaining dischargers in the Monitored Industry Program have extremely low loading (typically <100 mg/L of BOD) to the point where the cost the City incurs to collect samples exceeds the potential revenue collected from the user. These users have been assigned a permanent average as documented in past communications/letters between the City and the discharger. Under this tier, users are billed monthly using a “permanent long-term average.”

Below is a table summarizing the various discharger types and associated sampling frequencies:


Discharger Type	Expected BOD range	Sample Collection Frequency	Sample Collection Frequency	Permanent Monthly Average Applied?
Extremely High Strength Dischargers	> 5,000 mg/L consistently	Twice per month	Monthly average of all samples collected during the month	No
High Strength Dischargers	100-4,999 mg/L	Twice per quarter (eight times per year)	Averaged against 30 months of discharge data	No
Variably High Strength Dischargers	+/- 5,000 mg/L on a variable basis	Twice per quarter (eight times per year)	Averaged against 12 months of discharge data	No
Low Loading Dischargers	< 100 mg/L, consistent loading	Not sampled	30 months of past discharge data used to establish a “permanent monthly average”	Yes

Baseline Monitoring

For new Monitored Industrial Users, an agreeable baseline will be established before moving to any long-term averaging. This baseline may be formalized through the collection of samples eight or more times per year (two or more times per quarter) until a more appropriate monitoring approach (above) is identified.

Revenue Sample Collection

To compute each industry’s billing, the City collects “revenue samples” throughout the year and uses the results of those samples to inform billing. The City’s Environmental Inspectors in Source Control collect samples from the designated monitoring points following standard procedures. Most monitored industries are required to maintain their own automatic sampling device. City staff use that equipment for collecting revenue samples. For some industries, the City utilizes its own sampling equipment. Once samples are collected using the automatic sampling device, City staff deliver the samples to the RWF Laboratory for analysis.

Flow Data Reporting and Billing

Monitored Industrial Users report their flow monthly to their assigned Environmental Inspector typically by the fifth of each month. That data is compiled with the revenue sample data for bill processing by the 15th of the month. The Environmental Services Department Finance Program issues bills on a monthly basis.

Some special users who do not meet the high loading or flow criteria are placed in the Monitored Industry Program. This is because they cannot be appropriately billed on the tax roll. These users typically utilize an alternate water source or have an unusual seasonal variation that makes billing methodologies inaccurate. These users coordinate with Finance directly for billing.

Annual Updates and Tax Roll Changes

The Monitored Industry Program updates the Monitored Industrial Users list every June. Updates typically include adding new sites or removing sites that have closed. Sites may also be added or removed if their flows have changed above or below the 25,000 GPD threshold. All industries in the Monitored Industry Program receive an annual letter describing how they will be billed the following fiscal year. Additionally, the Monitored Industry Program communicates with monitored industries. Correspondence includes routine billing, rate notifications as required by Proposition 218, program updates, fact sheets, and projected rates.