Wis. Admin. Code Department of Natural Resources § NR 216.28 - Monitoring requirements

Current through March 28, 2022

(1) NON-STORM WATER DISCHARGES. The permittee shall evaluate all outfalls for non-storm water discharges into the storm drainage system beginning in the first year of permit coverage. Evaluations shall take place during dry periods. The following are additional requirements for evaluating non-storm water discharges:
(a) Any monitoring shall be representative of non-storm water discharges from the facility.
(b) One of the following monitoring procedures shall be followed:
1. End of pipe screening shall consist of visual observations made at least twice per year at each outfall of the storm sewer collection system. Observations shall be made at times when non-storm water discharges from the facility are considered most likely to occur. Instances of dry weather flow, stains, sludges, color, odor or other indications of a non-storm water discharge shall be recorded; or
2. A detailed testing of the storm sewer collection system may be performed. Testing methods include dye testing, smoke testing or video camera observation. Should the permittee use detailed testing as an alternative, the department shall require a re-test after 5 years or a lesser period as deemed necessary by the department.
(c) All permitted facilities shall maintain the results of their non-storm water evaluations on site. Facilities shall report the results of the initial non-storm water evaluations to the department within the SWPPP summary form required pursuant to s. NR 216.29(1) (e). Information reported shall include date of testing, test method, outfall location, testing results and potential significant sources of non-storm water discovered through testing.

Note: The department storm water pollution prevention summary Form 3400-167 contains a table for recording the results of the non-storm water discharge evaluations.

(d) Any permittee unable to evaluate outfalls for non-storm water discharges shall sign a statement certifying that this requirement could not be complied with, and include a copy of the statement in the SWPPP. The statement shall be submitted to the department.
(e) If a permittee identifies an unauthorized discharge of pollutants, the permittee shall immediately cease the discharge and contact the department to determine if a permit is required under s. 283.31 or 283.35, Stats.
(2) ANNUAL SITE INSPECTIONS. Permittees under this subchapter shall perform and document the results of an annual facility site compliance inspection. The inspection shall be adequate to verify that the site drainage conditions and potential pollution sources identified in the SWPPP remain accurate, and that the best management practices prescribed in the SWPPP are being implemented, properly operated and adequately maintained. Information reported shall include the inspection date, inspection personnel, scope of the inspection, major observations and revisions needed in the SWPPP.
(3) QUARTERLY VISUAL INSPECTION. Permittees under this subchapter shall perform and document quarterly visual inspections of storm water discharge quality at each outfall. Inspections shall be conducted within the first 30 minutes or as soon thereafter as practical, but not to exceed 60 minutes, after runoff begins discharging at the outfall. The inspections shall include any observations of color, odor, turbidity, floating solids, foam, oil sheen or other obvious indicators of storm water pollution. Information documented shall include: the inspection date, inspection personnel, visual quality of the storm water discharge and probable sources of any observed storm water contamination.
(4) STORM WATER SAMPLING AND ANALYSIS. Unless an alternative monitoring plan is required as part of the SWPPP, owners or operators of facilities covered under a tier 1 general permit issued under this subchapter or an individual WPDES permit issued under s. 283.31, Stats., containing tier 1 general permit requirements, or individual storm water discharge permits issued under s. 283.33(1) (a) and (d), Stats., shall perform annual chemical storm water sampling at each outfall for those residual pollutants listed in the permittee's SWPPP as required by s. NR 216.27(3) (j). The following are specific requirements for chemical storm water monitoring:
(a) The list of pollutants to be tested in the discharge at the outfall shall be identified in the facility monitoring plan portion of the SWPPP.
(b) When a facility has more than one outfall which have storm water discharges substantially similar based on consideration of industrial activity, significant materials and management, one outfall may be selected to represent the group of similar outfalls provided that this strategy has been clearly stated in the facility monitoring plan and that the representative outfall is clearly identified as such on the drainage base map. No more than 5 outfalls with discharges representative of storm water discharged from the facility need to be sampled.
(c) After review of the facility monitoring plan portion of the SWPPP, the department shall add additional pollutants to the monitoring list if it has cause to do so based on a reasonable probability that the pollutants will be present in storm water discharges from the facility. The department shall remove pollutants from the monitoring list if it determines that continued monitoring for the pollutant serves no further purpose. Chemical monitoring may be discontinued after submitting the second round of chemical monitoring results to the department with the annual facility site compliance inspection report unless the department directs the permittee otherwise. The department shall require additional chemical sampling within a tier 1 general permit for industrial facilities where chemical monitoring has shown a reasonable potential that the storm water discharge from an individual facility or a type of industry will exceed a water quality standard.
(d) Storm water samples shall be collected during the period of March through November from rainfall events that produce greater than 0.1 inch of rainfall and occur at least 72 hours after a previous rainfall of 0.1 inch or greater.
(e) Storm water samples shall be representative of the "first flush" of storm water runoff at the outfall using one of the following sampling methods:
1. Composite sample shall be collected during the first 30 minutes of runoff. At least 3 separate samples shall be collected for compositing, and the collection of samples shall be evenly spaced throughout the sampling period. Composite samples are required for all pollutants except those for which analytic techniques require grab samples.
2. A grab sample is required for all pollutants in storm water discharged from a detention pond or other structure that has greater than a 24-hour holding time for a representative storm. The grab sample shall be representative of the storm water discharge at the pond outfall.
3. An alternative sampling collection time specified by the department if the department determines it is necessary to obtain a representation sample of storm water runoff from the site.
(f) Monitoring samples shall be representative of the monitored discharge. Analytic testing shall be in conformance with ch. NR 219, unless an alternate procedure is approved by the department prior to the initiation of sampling.
(g) For each storm water measurement or sample taken, the permittee shall record and submit the following information to the department in the annual facility site compliance inspection reports described in s. NR 216.29(2):
1. The date, exact place, method and time of sampling or measurements.
2. The individual who performed the sampling or measurements.
3. The date the analysis was performed.
4. The name of the certified laboratory which performed the analysis.
5. The analytical techniques or methods used.
6. The results of the analysis.
7. The estimated duration of the rainfall event, in hours, and the estimated total amount of precipitation falling during the rainfall event, in inches.
(5) MONITORING EXCEPTIONS. The department may waive specific monitoring requirements if one of the following applies:
(a) An employee could not reasonably be present at the facility at the time of the snowmelt or runoff event, or those attempts to meet the monitoring requirement would endanger employee safety or well being.
(b) There were no snow melt or runoff events large enough to conduct a quarterly visual inspection at an outfall.
(c) The facility is inactive or remote, such as inactive mining operations where monitoring and inspection activities are impractical or unnecessary. At a minimum, the department shall establish an alternative requirement that the facilities make site inspections by a qualified individual at least once in every 3-year period.
(d) The permittee can demonstrate to the department's satisfaction that the sources of storm water contamination are outside of the facility's property boundary and are not associated with the facility's activities. The demonstration shall be presented in the SWPPP and submitted to the department for evaluation.


Wis. Admin. Code Department of Natural Resources § NR 216.28
CR 03-028: cr. Register July 2004 No. 583, eff. 8-1-04.

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