§ 12-81. Local limits.

(a)

It shall be unlawful to discharge into the POTW, any metals, chemicals or toxic substances in excess of the following limits:

(1)

Uniform concentration limits.

The following heavy metals and toxic materials in the form of compounds or elements in solution or suspension in concentrations exceeding the milligrams per liter (mg/L) daily maximum limit:

Pollutant	Daily Maximum Local Limit (mg/L)
Aluminum (Total)	57.74
Arsenic (Total)	0.88
Cadmium (Total)	0.77
Chromium (Total)	5.00
Copper (Total)	0.33
Lead (Total)	3.67
Mercury (Total)	0.04
Nickel (Total)	6.79
Zinc (Total)	2.79
Cyanide (Total)	0.77
Total Suspended Solids	8,084

 

(2)

Industrial contributory flow or mass allocation pollutant limitations.

The following pollutants will be allocated to industrial users on a case by case basis not to exceed the maximum allowable industrial loading (MAIL) established in the approved pretreatment program.

Pollutant

Selenium (Total)

Silver (Total)

Ammonia (Total)

Biochemical Oxygen Demand

Limits for these pollutants will be calculated using either the industrial contributory flow or mass allocation methods. The specific limitations will be established in the individual user discharge permits.

(3)

The control authority may set limits on a permit by permit basis for any other parameter that would pose a threat to water quality, health and safety, or the POTW or the discharge of which would otherwise result in violation of section 12-80 of this article, including but not limited to, priority pollutants found in the POTW influent at a concentration at or above 0.1 mg/L or numerical aquatic life criteria as defined by TCEQ.

(4)

Any radioactive wastes or isotopes without prior written permission from the environmental officer.

(b)

The above limits apply at the point where the wastewater is discharged to the POTW. The environmental officer may impose mass limitations in addition to, or in place of, the concentration-based limitations above.

(c)

The control authority may use a grab sample(s) to determine noncompliance with pretreatment standards.

(d)

Dilution is prohibited as a substitute for treatment. Except where expressly authorized to do so by an applicable pretreatment standard or requirement, no industrial user shall ever increase the use of process water, or in any other way attempt to dilute a discharge as a partial or complete substitute for adequate treatment to achieve compliance with a pretreatment standard or requirement. The environmental officer may impose mass limitations on industrial users which are using dilution to meet applicable pretreatment standards or requirements, or in other cases where the imposition of mass limitations is appropriate.

( Ord. No. 2432, § 6, 10-15-09 )