9. The Nitrogen Cycle
NH4
+
NO2
-
&
NO3
-
N2
Adding
Oxygen
Converts
Ammonium
to Nitrite and
Nitrate
Anoxic zones
force organisms
to use oxygen
bound in NO2
and NO3
Nitrogen gas
is released
to the
atmosphere
Wastewater
contains
Nitrogen
(Ammonium)
2NH4
+ + 4O2 NO2
- + NO3
- + 2H+ + 3H2O
The body rids itself of nitrogen as a waste product
10. Biological Treatment Process
$45.9 Million in 1992-1994
Return Activated Sludge
Secondary
Clarifiers
Second
Aeration
Basin
Second
Anoxic
Basin
Splitter
Box
First Aeration Basin
Internal Mixed Liquor Recycle
First Anoxic Basin
Intermediate
Pumping
Station
Diversion
StructurePrimary Effluent
Return Activated Sludge
Secondary
Clarifiers
Second
Aeration
Basin
Second
Anoxic
Basin
Splitter
Box
First Aeration Basin
Internal Mixed Liquor Recycle
First Anoxic Basin
Intermediate
Pumping
Station
Diversion
StructurePrimary Effluent
4X average
flow recycle
12. Current Budd Inlet Treatment Plant
Permit Limits
Parameter Permit Limits Loadings-
Based
Limits
Total Inorganic Nitrogen
(Nitrate and Ammonia)
3 mg/L
(since 1994)
338 lbs
288 lbs
Nutrient Removal Season April 1st to October 31st
Summer Biochemical
Oxygen Demand
7 mg/L 671 lbs
Spring and Fall
Biochemical Oxygen
Demand
8 mg/L 900 lbs
13. LOTT’s Nitrogen Loading on Budd Inlet
Source: Department of
Ecology, South Puget
Sound Dissolved Oxygen
Study
Good Morning –I am Laurie PierceOperations and Facilities Director forThe LOTT Clean Water AllianceI have been asked to talk with you today about the way technology has changed over the years at LOTT, And about the way LOTT plans to adapt to changing conditions as we move into the future.
The LOTT Clean Water Alliance is a not-for-profit corporation governed by representatives from the four partners we serve; Lacey, Olympia, Tumwater and Thurston County.
LOTT’s main treatment facility, the Budd Inlet Treatment Plant is located at the base of the Port of Olympia peninsula. It discharges into Budd Inlet, which is at the southernmost end of Puget Sound.The Budd Inlet Treatment Plant treats an average of 11 million gallons of wastewater each day to “advanced secondary” standards.Most treated water is discharged into Budd Inlet but a portion of the plant effluent, up to 1 mgd, is treated to Class A Reclaimed Water standards.
Prior to the original treatment plant, everything wet went into the bay.The original treatment plant came online in 1952 and provided the most basic level of treatment – primary sedimentation and disinfection.The solids were anaerobically digested and dried in sludge drying beds (which grew awesome tomatoes!)
LOTT was formed in 1976 in response to the federal Clean Water Act which also provided federal grant funds to upgrade treatment of discharges to work toward the goal of “fishable and swimable” water throughout the United States. Washington State supported the effort with additional grant funding for projects meeting federal Clean Water Act requirements. One of the grant funding conditions was that wastewater treatment be handled regionally. This was in recognition of well-established notions of economies of scale in wastewater treatment and the need for efficiency in implementing the Clean Water Act. Here is what the water in Budd Inlet looked like prior to nutrient removal at LOTT, and at lower annual average flows. (~9.0MGD)
Late 70’s construction brought the plant’s treatment process up to “secondary” standards
In 1982 the high purity oxygen secondary treatment plant came on line. During this period, LOTT discharged an average of 1300 pounds of nitrogen per day into Budd Inlet. I was going to show you what the original plant configuration was in a similar fashion but it turned out to be one box for the primary sedimentation basins and a round circle for the chlorine – it made for a pretty boring slide…
In the late 1980’s, as a result of water quality studies, Ecology issued an administrative order amending LOTT’s NPDES permit to mandate nitrogen removal.Algal blooms in the inlet were creating an excessive demand for Dissolved Oxygen during the critical months of April through October.The original (and very typical) permit limits of 30/30 TSS/BOD were amended to include an interim Total Inorganic Nitrogen Limit of 4 mg/L to be implemented by April, 1993 and ultimately 3 mg/L by April 1994.
The Nitrogen Cycle explains how the Budd Inlet Treatment Plant’s Secondary Treatment Process works
The upgrade to nitrogen removal cost LOTT approximately $45.9 Million in 1992 (which equates to over $72 M today).This plant in its current configuration is the second largest power consumer in Thurston County. Our annual power bill is in excess of $1.5M to run all LOTT facilities.This process was sized to accommodate potential future brewery loadings.The configuration of the existing de-nitrification system is excessive for current needs. Plans are underway to streamline this process.The large expense LOTT incurred to make nitrogen removal improvements in the 90’s illustrates the need for all utilities to conduct long-range planning and sound financial management.
The plant’s permit was reissued in 2005 and included a loadings-based nitrogen limit.These are the limits under which LOTT currently operates.The Total Inorganic Nitrogen limit is raised to 338 pounds/day during the colder “shoulder” months of April, May and October.The loadings-based permit structure also impacts how much flow LOTT can discharge into Budd Inlet. The cleaner we can get the water, the more we can discharge and vice versa.These are some of the most stringent TIN limits in the entire country, especially for plants with marine discharges like ours. A TMDL technical study has been completed, and implementation planning is underway. The low Dissolved Oxygen in this area of Puget Sound, which was one of the initial drivers for Ecology to steer LOTT toward nitrogen removal, continues to cause concern. The results of the TMDL implementation effort will more than likely have a significant impact on these limits and on the way LOTT will manage wastewater in the future.
Here is how LOTT compares to other treatment facilities discharging into the waters of Puget Sound.The average daily total inorganic nitrogen loading to Budd Inlet from LOTT this year is 258 pounds/day (average flow 10.28 MGD)Average of 352 lb/day over the last 16 years
The potential impacts of continuation of “business as usual” would have been disastrous for Budd Inlet and the fish and wildlife that depend on it as their habitat.So – Where do we go from here?There are many challenges ahead – Plan for Build-Out without knowing the impacts of: Deschutes/Budd Inlet TMDL Reclaimed Water Rule New permit limits Difficulty in land acquisition Land use permitting issuesCapital Planning – LOTT’s CIP covers property acquisition, capacity development, repairs, replacements and improvements to our system Planning period extends to 2053 – expected build-out of the UGA Helps LOTT avoid the large rate increases being see across the nation Designed to look far enough into the future to be able to make small, incremental rate adjustments now – so that when we reach 2030, 2040 and beyond, no matter how technology, regulations, or the economy may change, we will have sufficient funding to adapt to those changes It’s like steering an aircraft carrier – it takes a long time and a lot of space to make even small changes - so you have to plan your course far in advance – and once you get headed in a direction it can be difficult to make significant changes from your original course
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