City of Tucson
Comments on Municipal Stormwater Permit:
Page 5 of 35, 3.0 Limitations of Coverage, 3.3 Nonstormwater: The City requests that emergency fire
fighting flows be included in the permitted nonstorm discharges, as it was in the May 2010 Draft. In
addition, the City requests that the list of nonstorm flows that do not have to be prohibited discussed on
page 7 of 18 of the Fact Sheet be added to this section of the permit.
Page 6 of 35, 4.0 Surface Water Quality Standards, 4.2: Second paragraph, second sentence. Please
identify pollutants of concern. Are these the same as reoccurring exceedences?
Page 6 of 35, 4.0 Surface Water Quality Standards, 4.4: The City requests that if a recurring exceedence
exists that the City will either submit a proposed action plan within 30 days, or in the instance where the
action plan requires further study, that the City be allowed to petition the department for additional
time to prepare the action plan.
Page 9 of 35, 6.0 Special Conditions: The City requests that ADEQ evaluate the TMDL for Lakeside Lake
and consider if this TMDL is applicable for Stormwater runoff. The TMDL for the Lake is unusual in that it
measures parameters that are not traditional pollutants, including dissolved oxygen and chlorophyll. It
is highly unlikely that testing stormwater for these parameters will provide any meaningful results. The
City proposes to meet with ADEQ permit writers for Lakeside Lake and for the MS4 permit to determine
which TMDL requirements and wasteload allocations are appropriate for stormwater. Other issues
include which pollutants of concern at Lakeside are applicable to stormwater; and which tests should be
used. The TMDL pollutants of concern for Lakeside include dissolved oxygen, chlorophyll, phosphorus,
ammonia and nitrogen. However, basic information such as whether separate ammonia and nitrogen
tests would be required, and which analysis to use for phosphorus has not been developed. Until an
appropriate plan can be developed, the City requests an implementation schedule be created to provide
sufficient time to develop the appropriate approach. In addition, structural modifications may be
necessary to provide a sampling location where flow rates can be estimated. The City requests two years
to develop a strategy for implementing control measures as needed to manage stormwater flows into
the lake, establishing sampling parameters, determining sampling locations, and to seek Mayor and
Council approval for budget increases to fund stormwater sampling at Lakeside Lake.
Page 10 of 35, 7.3.3 Seasonal Stormwater Sampling: The language here requires that: “The city shall
sample stormwater discharging from the MS4 at the locations specified in Table 1 throughout the
permit term. Stormwater sampling shall commence on the first measurable storm event (as specified in
Section 7.3.1) in winter 2010.”
Because the current approved City budget did not include increased costs of stormwater sampling:
including increased number of parameters, longer sampling seasons requiring increased oncall and over
time pay, as well as cost increases and required City Manager approval for take home vehicles, the City
requests that the more extensive sampling be postponed until the second year of the permit. This will
Permit Comments 1
allow the Stormwater Section to submit a proposed increase in budget costs and provide the City with
an additional year to determine the source of these funds and which programs will need to be cut to
provide the increase in funding needed to implement the revised monitoring program.
Page 11 of 35, includes a definition of wet seasons. The City of Tucson requests that the establishment
of the monitoring seasons be based on conditions in Pima County. Our region has very distinct rainfall
patterns, which fall into two seasons, winter and monsoon and are separated by periods of drought
occurring in Spring and Fall. During the negotiations for the first permit, the City established that the
very different characteristics of summer and winter rainfall were substantial enough to separate
monitoring seasons into winter and summer. Winter rain events are slow moving and cover a large area.
Summer rains brought by monsoon conditions are high intensity, of short duration with limited area
coverage. Tucson receives the majority of rainfall during the summer rainy season, where thunderstorm
conditions typically develop every afternoon. The requirement for waiting 72 hours between sampling
events has often lead to a monitoring station being shut down when an otherwise qualifying rainfall
event occurs. The City requests that the 72 hour waiting period be applied only during the winter rainy
season.
In addition, the City requests that the rainy seasons be limited to time periods where there is a good
likelihood of rain. The expense of keeping sampling personnel on call for responding to rain events, not
to mention the public perception of stormwater vehicles being taken home year round is not justified to
capture 10 rain events per year (5 per season). In addition, NURP study found that for most of the
sampling locations, the variability in storm events masked any differences in stormwater runoff quality
between sampling sites located in distinct land use areas. By dividing the year into two seasons, storms
which occasionally occur during the dry seasons will muddy the data and make it more difficult to draw
conclusions on effectiveness of BMPs and prioritization of controls for different land uses.
Page 11 of 35 also includes language stating that sampling shall be conducted for the first three hours of
the storm event; however, on page 16 of 35, number 3 references a six hour sampling period. Please
address this apparent inconsistency. In addition, if the sampling period is 6 hours, this means that the
e-coli test, which has a hold time of only 6 hours, will expire before the samples can be transported to
the lab.
Page 13 of 35, The list of monitoring requirements includes language requiring sampling once wet
season beginning in Winter of 2010. Again, the City requests that the sampling for the larger list of
parameters commence after the next budget cycle or in Winter of 2011.
Page 16 of 35, 7.4 Assessment of Pollutant Loadings: First sentence, the first sentence in this section
refers to each monitored outfall. The City sampling stations are not all located at “outfalls to waters of
the US.” Instead, the sampling stations are located at concentration points of small to moderate sized
watersheds, based primarily on land use within the watershed. Please reword to read stormwater
monitoring stations, or monitoring locations.
Page 17 of 35, 7.5.2 Quality Assurance Manual: No date is provided here for the development of the
City’s manual. The City requests that this requirement be effective beginning in fiscal year starting July
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2012 to allow for sufficient time to budget assistance for preparing this manual, as current staff lack
expertise, and the City has a hiring freeze. Individuals in other City Departments may be able to assist,
however, due to staff shortages and layoffs around the City, most individuals are already performing
two or more jobs. Additional time is needed.
Page 21 of 35, 8.1.2 The 4th Year Annual Report, 1.Waters of U. S.: There are no Tucson area canals. The
Pima County Region lacks the irrigation canal network that characterizes Maricopa County. Please
remove this language.
Permit Comments 3