Kahului-Wailuku-Sprecklesville-Paia Municipal Disposal - Waste water by the numbers

  • An estimated 90% of resident wastewater is discharged to nearshore injection wells.

    On average, about 90% of resident wastewater is discharged into nearshore injection wells at the Kahului Wastewater Reclamation Facility, while about 10% is used for in-plant recycling. Detailed UIC water quality and County of Maui plant flow reports here

    Space
  • Kahului WWRF injected Total Nitrogen & Total Phosphorus 1999 - 2021

    Injected nutrient concentrations in Kahului from 1999-2021 showed a slight downward trend in Total Nitrogen ending up around 10 mg/L. Total Phosphorus trends are steady over the years around 2 mg/L. Detailed UIC water quality and County of Maui plant flow reports here

    Space
  • Kahului WWRF total Plant Flow, Injection Well Flow and Reuse Flow (MGD)

    Injected flowrates in Kahului from 1999-2021 showed a steady plant flow of about 6 MGD. and < 0.5 MGD reuse, with over 4.5 MGD going to nearshore injection wells. Detailed UIC water quality and County of Maui plant flow reports here

    Space
  • Kahului WWRF Total Plant injected and Reuse Nutrient Total Nitrogen + Total Phosphorus Mass Loading (lbs/year)

    From 1999-2021 the Kahului Wastewater Reclamation Facility showed an overall decline in total plant nutrient mass discharged and nutrient mass injected, down to about 150,000 lbs. or about 75 tons of dissolved nutrients per year as Nitrogen and Phosphorus. Detailed UIC water quality and County of Maui plant flow reports here

    Space
  • Kahului WWRF injected coliform (MPN/100mL) 1999 - 2021 shows indicator bacteria skyrocketing after chlorine disinfection was ceased in 2018

    Fecal coliform cell counts from 1999-2021 shows injected municipal wastewater in Kahului appears to have been consistently disinfected until around 2018, after which fecal coliform cell counts are routinely measured above the testing detection limit of 2419.6 Most Probable Number of colony-forming (or infection forming) units per 100mL of wastewater. Detailed UIC water quality and County of Maui plant flow reports here

    Space
  • Kahului-Wailuku Wastewater Reclamation Facility By The Numbers

    Kahului Wastewater Reclamation Facility Flow Summary

    April 2020 total flow (MGD)Ave. 2020 reuse flow (MGD)Est. April 2020 injection flow (MGD)2020 injected TN (mg/L)2020 injected TP (mg/L)
    5.37 0.53

    4.85

    10.27

    3.03

    The average daily plant flow at the Kahului Wastewater Reclamation Facility in 2020 was over 5 MGD, reuse was about 0.5 MGD, and average injection over 4.8 MGD. Total Nitrogen in the same period was over 10 mg/L and Total Phosphorous was over 3 mg/L. Detailed UIC water quality and County of Maui plant flow reports here.


    Injected Flow and Nutrients Per Census Resident

    Inj. nutrients / census resident / year (lbs/year)Inj. wastewater / census resident / year (gallons/year)Inj. wastewater / census resdient / day (gallons/day)

    4.0

    36,389

    100

    The total estimated nutrient mass injected per census resident per year at the Kahului Wastewater Reclamation Facility is about 4 pounds of dissolved nutrients per year. Each resident contributes about 36K gallons to injection per year in Kahului, averaging about 100 gallons per resident per day. Detailed UIC water quality and County of Maui plant flow reports here.


    Injected Fecal Coliform Cell Counts per Census Resident

    Injected coliform cell counts (MPN/100mL)Total inj. coliform cell counts / resident (MPN/year)

    >2419.6

    >3,332,1923,119


    Injected fecal coliform Most Probable Number of colony forming (infection forming) units is recently measured at above 2419.6 per 100 mL, which is above the detection limits for the test used. Total injected fecal coliform colony forming units per census resident is over 3 Billion cells per year. Detailed UIC water quality and County of Maui plant flow reports here.

  • Kahului-Wailuku Municipal Wastewater Reclamation Facility Compliance Reporting History
    datetotal flow (MGD)reuse flow (MGD)injection flow (MGD)Total Nitrogen (mg/L)Total Phosphorus (mg/L)coliform (MPN/100mL)
    6/14/99 5.147 0.424 4.723 14 1.9 < 2
    11/17/99 5.458 0.437 5.021 14 2 < 2
    5/17/00 5.507 0.37 5.137 10.99 2.2 < 2
    11/27/00 6.725 0.385 6.34 17.8 2.38 < 2
    6/7/01 5.2 0.493 4.707 19.6 2.95 no data
    12/11/01 5.274 0.431 4.843 14.9 2.6 2
    5/23/02 5.317 0.4 4.917 13.4 2.63 > 1600
    12/27/02 4.799 0.39 5.409 21.8 2.72 < 2
    5/28/03 4.752 0.407 4.345 15.7 2.84 < 2
    12/17/03 5.009 0.413 4.596 7.62 3.26 < 2
    5/7/04 4.954 0.399 4.555 3.41 2.48 < 2
    12/7/04 4.756 0.277 4.479 9.93 0.22 < 2
    5/26/05 4.802 0.24 4.562 10.27 0.46 < 2
    11/15/05 4.875 0.189 4.686 9.29 0.327 < 2
    5/15/06 4.933 0.249 4.684 8.49 1.65 2
    11/27/06 5.217 0.213 5.004 8.83 0.81 < 2
    5/11/07 4.495 0.289 4.206 3.71 1.67 < 2
    11/9/07 4.776 0.238 4.538 8.19 1.25 < 2
    6/13/08 4.939 0.338 4.601 22.12 1.15 2
    11/13/08 4.364 0.111 4.253 10.81 0.47 < 2
    5/27/09 4.496 0.154 4.342 8.38 0.46 < 2
    11/25/09 4.225 0.291 3.934 11.34 1.13 < 1.8
    05/10/10 4.016 0.162 3.854 9.2 0.5 2
    12/03/10 4.085 0.161 3.924 13.77 0.56 < 1.8
    05/26/11 4.016 0.162 3.854 12.14 0.5 130
    11/30/11 3.842 0.167 3.675 13.52 0.47 < 1.8
    05/24/12 3.964 0.161 3.803 10.06 0.47 < 1.8
    11/30/12 3.868 0.317 3.551 11.38 0.3 < 1.8
    05/14/13 4.620 0.346 4.274 9.69 0.7 < 1.8
    11/14/13 4.237 0.249 3.988 10.33 0.41 < 1.8
    05/22/14 3.441 0.266 3.175 11.82 1.76 < 1.8
    11/14/14 4.839 0.21 4.629 9.9 2.5 < 1.8
    05/08/15 5.011 0.37 4.641 9.1 0.42 < 1.8
    11/16/15 5.127 0.423 4.704 6.69 0.6 < 1
    05/26/16 5.348 0.467 4.881 13.53 2.5 < 1
    11/18/16 5.376 0.433 4.943 9.4 0.9 4.1
    05/30/17 5.856 0.194 5.662 10.12 2.5 no data
    12/27/17 5.85 0.179 5.671 13.23 2.3 no data
    06/06/18 5.447 0.155 5.292 8.81 0.6 < 1
    12/03/18 5.523 0.178 5.345 8.23 0.62 > 2419.6
    05/23/19 5.345 0.145 5.2 10.31 3.05 1553.1
    11/08/19 5.828 0.367 5.461 12.38 4.56 > 2419.6
    12/09/20 5.373 0.526 4.847 10.27 3.03 no data
    05/13/21 5.956 0.264 5.692 10.47 1.17 > 2419.6
    11/15/21

    5.392

    0.269

    5.123

    10.42.16>2419.6
    04/20/22

    5.448

    0.140

    5.308

    15.530.490>2419.6
    10/18/22---13.04.35>2400

How does the water I flush affect our reefs?