8.d) Engineering Activity Report-March 2013 . 8. �-�
Engineering Activity Report
, ` ,'�
March 1 through March 31, 2013 �?`�-��
Phil Gravel, City Engineer C1�D�
(651) 604-4885 phil.gravel@stantec.com
The purpose of this report is to provide information on recent engineering activity in Scandia.
Streets
• Answered questions from contractors regarding bids for the 2013 Seal Coat project. Bids will
be received on April 3`d
• Worked with Tim Kieffer on specifications for 2013 gravel quotes for gravel surfacing on Old
Marine Trail and Parade Avenue.
• Worked with Tim Kieffer on specifications for 2013 bituminous patching.
Sewer
• Worked with Clint Jordahl and Andy Riemer to complete spring well sampling on the
Anderson-Erickson system. Sampling was completed on Wednesday, March 20"'. Test
results from Pace Labs usually take about 3 weeks after the samples are submitted.
• Reviewed draft Anderson-Erickson Permit from Washington County.
• Drafted possible sewer ordinance revisions. Will provide recommendations to Kristina and
Tim in April for the April 24"'Wastewater Advisory Committee meeting.
Miscellaneous
• Researched Lilleskogen Park survey and wetland delineation history.
• Regular phone conversations with Tim Kieffer.
City of Scandia—Engineering Activity ReF�ort �
Stantec Consulting Services Inc.
2335 Highway 36 West
St. Paul MN 55113
Tel: (651)636-4600
Fax: (651)636-1311
�n�
April 10,2013
Kristina Handt,Administrator
Ciry of Scandia
14727 209th Street N
Scandia, MN 55073
Re: Anderson/Erickson Sewage Treatment System (201 Collector System)
Monitoring Well Sampling Infortnation
Our Project No.: 193802153
Dear Kristina:
As part of on-going monitoring of the Anderson/Erickson System Sewage Treatmerrt System,samples were
pulied from the deep monitoring wells in March of 2013. This letter presents a summary of the sampling
resufts. A full copy of the lab reports have been transmitted to Tim Kieffer and you previously via an e-mail
message.
The attached Tables present a summary of the March 2013 sampling as well as previous samplings. Table 1
presents infoRnation on the groundwater field data. Table 2 presents information on the analytical test results
from the samples.
MONRORING WELL AND GROUNDWATER INFORMATION
The Anderson-Erickson treatment system includes 4 sets of nested monitoring wells and shallow piezometers
along with one additional shallow piezometer. The wells and piezometers are used to monitor the
performance of the system. The wells and piezometers are useful in monitoring groundwater qualiry(i.e.
nitrate nitrogen levels),determining groundwater flow direction, and detecting ff there is"mounding"beneath
the system.
The attached Tables 1 and 2 show the results of past well measuremeM and sampling. The March 2013
sampling did not have any nkrate concentrations above the drinking water standard. The March 2013
ammonia levels are somewhat elevated, but they have been consistent throughout the testing,so the results
may be indicative of background levels. There is no drinking water standard for ammonia.
It appears that the previous high nitrate levels have been brought under corrtrol. This could likely be the
resuft of the system being operated to let portions of the system"resY'. The system is designed so that one of
the three cells should be off-line at any given time.
Given the latest test results,we feel that it would be prudent to continue sampling the monitoring wells one to
three times a year to make sure that the permitted indicator levels are met. Note that the permit with
Washington County requires three sampling a year. You may want to consider trying to get that frequency
�educed.
SYSTEM FLOW INFORMATION
The treatment system was installed in 1987. There have been several reports and studies over the past 10
years that have evaluated the design capacity of the system and possible methods of system expansion. The
current system Operating Permit with Washington County lists a system design flow of 6,700 gallons,a target
peak flow of 8600 gallons and a target average flow of 5300 gallons.
�t�t
April 10,2013
Kristina Handt,City Administrator
P&J8 2 Of Z --- V:\1938�active\1938021531Communications\Correspondence�2013-April,update letter
A review of daily flow information was completed last summer. At that time,daily flows ranged from 1,410
gallons to 7,622 gallons. The high 7-day rolling average was 4,958 gallons. Flow measurement data should
be monitored in the future to make sure that the system operates under the targeted flow limits.
RECOMMENDATIONS
At this time,we have the following recommendations regarding the operations and monitoring of the
Anderson/Erickson Sewage Treatment System:
• Continue daily flow monitoring in the non-winter periods. In order to reduce flows,the c'rty should
consider a program to educate the system users on water conservation measures. Education on
water conservation options could be particularly useful during the peak use periods in the summer.
• Complete a round of well sampling in July 2013. You should work with EcoCheck to get them trained
to do the sampling as part of their operations work.
• Pay special attention to well sampling results(Nitrate levels)when the operators begin reusing the
drainfield cell that produced the original high nitrate levels.
• Continue to take steps to complete the system repaidmaintenance recommendations included in the
March 2012 Condition and Capacity Assessment Report. Consuft with the EcoCheck to see ff they
have recommended maintenance improvements. Refer to required maintenance listed in the County
Permit.
• Take steps to repair the monitoring well sampling pumps. In deep well A the pump is inoperable and
appears to be stuck in the well. Caution needs to be taken in attempting to remove the pump to
make sure the well is not damaged or ruined.
As presented in previous reports and memos,the Anderson/Erickson system will require some treatment
system maintenance improvements in the near future. Long-term system expansio�mprovement
recommendations to meet the needs of the entire AndersoNErickson service area should be delayed until
addftional flow and well monitoring information is available.
Please contact Clint Jordahl or me if you have any questions or require any additional information.
Sincerely,
STANTEC
/ �����
Phil Gravel, PE
cc: Tim Kieffer, Public Works
Attachments: Tables 1-2
R
TaWe 1
Groundwater Field Data Summary
Anderson/E�ickson S�rstem
Stanbec Project 193802153
MDN Top of Deptlt to
We0 Unique Well Weh Wser Groundwater Groundwater Conductivity ,
Idet�tifi� < Number De a Elevation Dabe ' from TOR Elevation ho cm H, Tert�".°G
3/22/12 47.96 938.57 1,966 7.21 9.87
7/17/12 48.22° 93631 - - -
A-Deep 438453 59° 986.53 7/26/12 48.12 936.41 1,030 7.30 11.63
10/17/12 48.51 938.02 1,117 7.29 10.00
3/20/13 Water level was below pump,which was inoperaNve and studc in well
A-Shalbyv 42i449 13.9 986.69 Ap Debes Dry - - - --
3/22/12 46.99 939.41 2,448 6.92 10.30
7/17/12 47.24° 939.16 - - -
B-Deep 438454 57.5° 986.40 7/26/12 47.17 939.23 1,569 7.14 12.06
10/17/12 47.40 939.00 1,422 7.14 9.93
3/20/13 >48.81` <937.59` 1,313 7.50 8.50
3/22J12 11.22 975.98 - -
7/17/12 Dry° - - - -
B-ShaUcw 421450 14.1 987.20 7/26/12 12.95 974.25 - -- -
!0/17/12 Dry - - -- -
3/20/13 Dry - - - -
3/22/12 51.95` 937.83 637 7.24 30.57
7/17/12 51.85° 937.93 - - -
C-Deep 438455 57.9 989.78 7/26/12 51.74 938.04 449 7.34 14.24
10/17/12 52.35 937.43 464 730 10.67
3/20/13 53.22 936.56 465 7.70 8.54
asnaeow 4oa�4s ia.z �0.4o ai oates ory _ _ _ _
3/22/12 51.42` 937.65 1,967 7.14 10.64
7/17/12 51.58° 937.49 -- - -
D-Oeep 438452 62.4 989.07 7/26/12 51.28 937.79 1,187 7.15 11.42
10/17/12 5232 936.75 1,373 7.18 9.77
3/20/13 53.04 936.03 1,275 9.02 8.48
D-Shaiorr 404749 14.0 988.60 M Dabes Dry - - - -
EShallow 404750 15.5 990.42 AII Dates Dry - -- - -
a-Meas�xed from top of riser unless otherNrise indicated
b-Pump stuck in well,depth from construcdon reoords and does not indude riser sdckup
c-Pump removed to measure water level,full recharge not verified prior to reoording water level
d-7/17/12 groundwater measuremer�provided by Natural Systems Utiiides,MN lLC(EcoCheck)
e-Pump is stuck in well and water level was below pump.Measured depth reported is depth to obsU�uctlon
TaWe 2
Groundwaber Analytical Results
Anderson/Erickson Sytstem
Stantec Project 193802153
(all values reporbed as mg/L)
Nitrate Plus Totat Kjeldahl
Well Nitrite Chbride Ammonfa Nitrogen Nitrogen
Ider�fier :.„�Date_.. . , N + Cl- NH
3/22/12 16.2 377 <0.04 <1
7/26/12 1.6 237 <0.04 <1
A���p 10/17/12 1.2 241 0.084 <1
3/20/13 Dedicated bladder pump was inoperable and is studc in weli
3/22/12 19.6 493 <0.04 <1
7/26/12 1.3 426 <0.04 <1
B-�p 10/17/12 2.3 343 0.25 <1
3J20/13 2.8 342 0.11 <1
3/22/12 1.4 7.7 <0.04 <1
7/26/12 0.46 4.3 <0.04 <1
C-�p 10/17/12 0.46 3.2 0.095 <1
3/20/13 0.50 3.0 0.050 <1
3/22/12 12.9 415 <0.04 <1
7/26J12 0.73 327 <0.04 <1
���p 10/17/12 0.66 364 0.045 <1
3J20/13 0.78 347 0.052 <1
Duplicabes 3/20/13{well C) 0.52 3.2 0.046 <1
< Parameter not detected at a concentraGon greater than or equal to the reporting limit indicated