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A. The 2019 state of Washington Department of Ecology’s Storm Water Management Manual for Western Washington is hereby adopted by reference, except as modified herein for consistency with the requirements of the NPDES Western Washington Phase II municipal storm water permit, and is hereinafter referred to as “the manual.”

B. General. BMPs (best management practices) shall be used to control pollution from storm water. BMPs shall be used to comply with the standards in this chapter. BMPs are in the manual.

C. Deviations. In order to achieve goals of low impervious surface development or other source reduction preventative actions or design, deviations from Public Works Standards may be considered and authorized in accordance with the procedures and requirements of such standards. Deviations that require approval under the land use code, such as parking and landscaping standards, will require an administrative adjustment of standards in accordance with the procedures for the applicable standards.

D. Illicit discharges to storm water drainage systems are prohibited. No person shall throw, drain, or otherwise discharge into the MS4 any pollutants or water containing pollutants, other than storm water.

E. The following categories of nonstorm water discharges are prohibited unless the stated conditions are met:

1. Discharges from potable water sources, including but not limited to water line flushing, hyperchlorinated water line flushing, fire hydrant system flushing, and pipeline hydrostatic test water. Planned discharges shall be dechlorinated to a total residual chlorine concentration of 0.1 ppm or less, pH-adjusted, if necessary, and volumetrically and velocity controlled to prevent resuspension of sediments in the MS4.

2. Discharges from lawn watering and other irrigation runoff. These discharges shall be minimized through, at a minimum, public education activities and water conservation efforts.

3. Dechlorinated swimming pool, spa and hot tub discharges. The discharges shall be dechlorinated to a total residual chlorine concentration of 0.1 ppm or less, pH-adjusted and reoxygenized if necessary, volumetrically and velocity controlled to prevent resuspension of sediments in the MS4. Discharges shall be thermally controlled to prevent an increase in temperature of the receiving water. Swimming pool cleaning wastewater and filter backwash shall not be discharged to the MS4.

4. Street and sidewalk wash water, water used to control dust, and routine external building wash down that does not use detergents. Discharges from these sources shall be minimized through public education activities in accordance with the permit. At active construction sites, street sweeping must be performed prior to washing the street.

5. Other nonstorm water discharges. The discharges shall be in compliance with the requirements of the storm water pollution prevention plan reviewed by the city, which addresses control of construction site de-watering discharges.

6. Solid or liquid wastes thrown, drained or otherwise discharged directly or indirectly into the municipal storm drain system and/or surface and ground waters. Examples of prohibited contaminants include, but are not limited to, the following:

a. Trash or debris;

b. Construction materials;

c. Petroleum products including but not limited to oil, gasoline, grease, fuel oil and heating oil;

d. Antifreeze and other automotive products;

e. Metals in either particulate or dissolved form;

f. Flammable or explosive materials;

g. Radioactive material;

h. Batteries;

i. Acids, alkalis, or bases;

j. Paints, stains, resins, lacquers, or varnishes;

k. Degreasers and/or solvents;

l. Pesticides, herbicides, or fertilizers;

m. Steam cleaning wastes;

n. Soaps, detergents, or ammonia;

o. Domestic animal wastes;

p. Recreational vehicle waste;

q. Animal carcasses;

r. Food wastes;

s. Bark and other fibrous materials;

t. Lawn clippings, leaves, or branches;

u. Silt, sediment, concrete, cement or gravel;

v. Dyes (discharged without prior notification and approval of the city);

w. Chemicals not normally found in uncontaminated water;

x. Any other process-associated discharge except as otherwise allowed in this section; and

y. Any hazardous material or waste not listed above.

F. The following categories of nonstorm water discharges are exempt from the discharge prohibitions established by this section:

1. Diverted stream flows;

2. Rising ground waters;

3. Uncontaminated ground water infiltration (as defined at 40 CFR 35.2005(20));

4. Uncontaminated pumped ground water;

5. Foundation drains;

6. Air conditioning condensation;

7. Irrigation water from agricultural sources that is commingled with urban storm water;

8. Springs;

9. Uncontaminated water from crawl space pumps;

10. Uncontaminated water from footing drains;

11. Flows from riparian habitats and wetlands;

12. Nonstorm water discharges covered by another NPDES or state discharge permit; and

13. Discharges from emergency firefighting activities.

G. Prohibition of Illicit Connections.

1. The construction, use, maintenance, or continued existence of illicit connections to the storm drain system is prohibited.

2. This prohibition expressly includes, without limitation, illicit connections made in the past, regardless of whether the connection was permissible under law or practices applicable or prevailing at the time of connection.

3. A person is considered to be in violation of this section if the person connects a line conveying sewage to the MS4, or allows such a connection to continue. (Ord. 1205-22 § 4, 2022; Ord. 1179-20 § 2; Ord. 1112-15 § 2; Ord. 1032-10 § 2).