HomeMy WebLinkAboutWOODWARD TECHNOLOGY CENTER - LINK-N-GREENS OVERALL DEVELOPMENT PLAN - ODP120002 - CORRESPONDENCE - MEMO / P & Z BOARD■ Odor Testing —Odor characterization tests were conducted prior to, and after
plant startup. The odor tests were conducted by St. Croix Sensory, Inc. utilizing
the ASTM international E679-4, Standard of Practice for Determination of Odor
and Taste Thresholds by a Forced -Choice Ascending Concentration Series
Method of Limits.
Table A: Odor Characterization Results at
Mulberry Water Reclamation Facility
Pre -Startup (I a/5/2012)
Post -Startup (0811orml1)
Sample
Description
Detection
Threshold
Recognition
Threshold
Hcdonic
Tone
Detection
Threshokt
Recognition
Throsbold
Iledonic
Tone
Characterisation
South Boundary
85
45
-1.6
40
20
-0.8
Chemical, Medicinal,
Offensive
West Boundary
65
40
.1.6
BS
45
-1.0
Ch Otrecsieditinal,
vc
East Boundary
35
22
-0.6
75
40
-1.0
CbanOffal, Medicinal
Oersivc
42-inch by-pass
85
45
-1.0
140
70
-0.6
cd
ChemO Tsive al.
Definitions:
Detection Threshold — the number of times a sample must be diluted to be just above the limit
of a person's ability to smell the odor.
Recognition Threshold —the number of times a sample must be diluted to be just above the
limit of a person's ability to characterize an odor.
Hedonic Tone —the measure of the pleasantness or unpleasantness of an odor. An arbitrary but
common scale for ranking odor by hedonic tone is the use of a 21 point scale:
+10 Pleasant
0 Neutral
-10 Unpleasant
■ Discussion — Analysis of the threshold values is difficult and the fluctuation
between the values could be attributed to temperature, wind direction during
sampling, and background odors. Comparison of the hedonic tones between the
sampling dates indicates that the intensity of the odors between the two test
dates was relatively the same. A more definitive confirmation of the
effectiveness of the current odor control facilities is the fact that the Utility
has received no odor complaints attributed to the Mulberry facility since the
plant was re -commissioned in July 2011.Observations by plant staff over the
past year indicate that odors should not be detectable beyond the plant
boundaries under normal operating conditions.
o The reduced buffer exceeds the regulations and policies of the Colorado Water Quality
Control Division.
As a result, we would like to request an alternative setback distance, acknowledging the upgrades and
treatment technologies that have been implemented, to be substituted for the setback distance
within the standard 3.4.2(8) - Setbacks from Domestic Wastewater Treatment Works to Habitable
Structures.
Specific findings for the Alternative Compliance Request
■ The plan will equally well or better accomplish the purpose of this Section than would a plan
which complies with the standards of this Section.
o Since the 1000' standard was established based on the previous operations of the
facility before its upgrades, and significant upgrades with aggressive odor controls and
additional treatment technologies have been implemented, the proposed 500' setback
distance reflects the current condition of the facility equally well or better than the
setback distance in the standard.
■ The plan acknowledges mitigating factors that now exist to counter the potential for odor
problems and/or aerosol drift.
o Due to the fact that existing businesses and residences along Riverside Drive were
located within the 1000-foot setback, the 2008 Mulberry Improvements Project
included substantial upgrades to the plant odor control equipment. These include the
following:
• Process Isolation —Odorous processes in the preliminary, primary, and
secondary treatment areas were covered to prevent exposure to the
atmosphere. Odor control piping, both above and below ground provides
ventilation between these areas and the odor control process.
■ Primary Odor Control —Air from the most odorous processes is drawn through
an organic biofilter by two odor control fans. The air is first humidified, and then
drawn through a 6-foot thick mixture of wood chips and compost. This media
provides an environment for the growth of sulfur -reducing bacteria to treat the
hydrogen sulfide and mercaptans which are the primary odor -causing
constituents in these areas.
• Secondary Odor Control -Discharge from primary odor control system is mixed
with air drawn from the activated sludge basin and pushed through the
secondary odor control system. This consists of a 15-foot diameter horizontal -
flow activated carbon filter. The activated carbon strips any remaining hydrogen
sulfide prior to discharge into the atmosphere.
Considerable effort went into designing system redundancy and ease of
maintenance. The primary odor control can be bypassed to the secondary
system during maintenance periods and the secondary odor control is divided
so one side can remain online while the other is being maintained.
Request for Alternative Compliance with 3.4.2(B) regarding
Setbacks from Domestic Wastewater Treatment Works to Habitable Structures
Link-n-Greens ODP
August 30, 2012
Concurrent with the Link-n-Greens ODP, we would like to request the following Alternative Compliance
with Section 3.4.2(B) regarding Setbacks from Domestic Wastewater Treatment Works to Habitable
Structures.
Current Standard
3.4.2(B) - Setbacks from Domestic Wastewater Treatment Works to Habitable Structures —
Unless specifically authorized pursuant to the provisions of paragraph (C) below, the minimum
horizontal distances set forth in subparagraph (2) of this subsection shall be maintained between the
various kinds of wastewater treatment works listed in said subparagraph and any of the following uses:
(a) any residential use;
(b) any commercial/retail use except frozen food lockers, enclosed mini -storage facilities and
properties used principally as parking lots or parking garages;
(c) any industrial use except warehouses, properties used for recreational vehicle, boat or truck
storage, composting facilities, outdoor storage facilities, junkyards, transport terminals,
recycling facilities, and resource extraction;
(d) any institutional/civic/public use except cemeteries, golf courses, public facilities, parks,
recreation and other open lands, places of worship or assembly; and
(e) any accessory/miscellaneous uses except agricultural activities, farm animals, satellite dishes
(greater than thirty-nine [39] inches in diameter), wireless telecommunications equipment and
wireless telecommunications facilities.
Description of need for Alternative Compliance
The Link-n-Greens ODP is being established to accommodate a new campus for Woodward. The current
setback for the Mulberry Water Reclamation Facility is 1000' (see attached exhibit). A portion of the
development site falls within the 1000' setback line. However, the Mulberry Water Reclamation Facility
has been significantly upgraded with aggressive odor controls and additional treatment technologies. A
reduced buffer from 1000' to 500' acknowledging the effects of these measures is proposed.
City v
Fort Collins
(2) Review Criteria. To approve an alternative plan, the decision maker
must first find that the proposed alterative plan accomplishes the
purposes of this Section equally well or better than would a plan which
complies with the standards of this Section.
In reviewing the proposed alternative plan, the decision maker shall
consider any mitigating factors that exist to counter the potential for odor
problems and/or aerosol drift, including, without limitation, structural,
chemical or technological mitigation occurring at the subject wastewater
treatment works, established vegetation barriers and/or walls, berms, or
other topographic features sufficient to serve as mitigation for odor
problems and/or aerosol drift. In order to assist the decision maker in
evaluating the proposed mitigation factors the Utilities Executive Director
shall submit a written recommendation regarding such mitigation factors,
which recommendation shall include the technical analysis and reasoning
used in support of the Utilities Executive Director's recommendation.
(Ord. No. 204, 2001 § 16, 12/18/01; Ord. No. 080, 2011, §2, 9/6/2011)
The technical analysis and reasoning submitted with the request has been reviewed by Utilities
staff and it is believed that sufficient mitigation will be accomplished meet the Alternative
Compliance standard with the understanding that:
a. The applicant acknowledges that they are building next to a wastewater treatment plant;
b. Plant upsets are possible that may cause odors;
c. Plant maintenance will be required where the odor control may be off for short periods of
time; and,
d. The applicant must inform future tenants of the aforementioned facts.
Based on this information, I recommend approval of the proposed alternative plan.
1
I �P�
City of
Fort`Collins
��
MEMORANDUM
DATE: September 5, 2012
Uturtfes Executive Director
electric • stormwater . wastewater.
700 Wood St.
PO Box 580
Fort Collins, CO 80522
970.221.6702
970.416.2208
970.224.6003 TDD
utilitiesCa fcaov.com
fcgov. corn/utitities
water
TO: Planning & Zoning Board
FROM: Brian Janonis, Utilities Executive Director
RE: Link-N-Greens ODP request for Alternative Compliance reduction to the Land
Use Code Air Quality Odor Buffer
The applicant for the redevelopment of the Link-N-Greens site has requested a reduction of the
Air Quality odor buffer distance from the Mulberry Water Reclamation Facility as part of their
Overall Development Plan submittal. The setback distance is set in the Land Use Code section
3.4.2(B) while Alternative Compliance to this standard is allowed per Section 3.4.2(C), as shown
below:
3.4.2 Air Quality taut
(A) General Standard The project shall conform to all applicable local, state and
federal air quality regulations and standards, including, but not limited to, those
regulating odor, dust, fumes or gases which are noxious, toxic or corrosive, and
suspended solid or liquid particles.
(B) Setbacks from Domestic Wastewater Treatment Works to Habitable
Structures.
(1) Unless specifically authorized pursuant to the provisions of paragraph
(C) below, the minimum horizontal distances set forth in subparagraph (2)
of this subsection shall be maintained between the various kinds of
wastewater treatment works listed in said subparagraph and any of the
following uses:
(a) any residential use;
(b) any commercial/retail use except frozen food lockers, enclosed
mini -storage facilities and properties used principally as parking
lots or parking garages;
(c) any industrial use except warehouses, properties used for
recreational vehicle, boat or truck storage, composting facilities,